166261428 has 72 divisors (see below), whose sum is σ = 446918472. Its totient is φ = 51935232.

The previous prime is 166261427. The next prime is 166261429. The reversal of 166261428 is 824162661.

166261428 is a `hidden beast` number, since 1 + 6 + 626 + 1 + 4 + 28 = 666.

It is an interprime number because it is at equal distance from previous prime (166261427) and next prime (166261429).

It can be written as a sum of positive squares in 4 ways, for example, as 41447844 + 124813584 = 6438^2 + 11172^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 166261392 and 166261401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166261427) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 193576 + ... + 194432.

It is an arithmetic number, because the mean of its divisors is an integer number (6207201).

Almost surely, 2^166261428 is an apocalyptic number.

166261428 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 166261428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (223459236).

166261428 is an abundant number, since it is smaller than the sum of its proper divisors (280657044).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

166261428 is a wasteful number, since it uses less digits than its factorization.

166261428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1201 (or 1196 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 166261428 is about 12894.2401094442. The cubic root of 166261428 is about 549.8748233033.

The spelling of 166261428 in words is "one hundred sixty-six million, two hundred sixty-one thousand, four hundred twenty-eight".