166261840 has 40 divisors (see below), whose sum is σ = 392340960. Its totient is φ = 65510016.

The previous prime is 166261829. The next prime is 166261841. The reversal of 166261840 is 48162661.

It is a tau number, because it is divible by the number of its divisors (40).

It is a hoax number, since the sum of its digits (34) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 166261796 and 166261805.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166261841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10150 + ... + 20869.

It is an arithmetic number, because the mean of its divisors is an integer number (9808524).

Almost surely, 2^166261840 is an apocalyptic number.

166261840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166261840 is an abundant number, since it is smaller than the sum of its proper divisors (226079120).

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

166261840 is a wasteful number, since it uses less digits than its factorization.

166261840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31099 (or 31093 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 166261840 is about 12894.2560855600. The cubic root of 166261840 is about 549.8752775042.

The spelling of 166261840 in words is "one hundred sixty-six million, two hundred sixty-one thousand, eight hundred forty".