166856440 has 16 divisors (see below), whose sum is σ = 375427080. Its totient is φ = 66742560.

The previous prime is 166856419. The next prime is 166856441. The reversal of 166856440 is 44658661.

It is a happy number.

166856440 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 4171411 = 166856440 / (1 + 6 + 6 + 8 + 5 + 6 + 4 + 4 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 166856393 and 166856402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166856441) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2085666 + ... + 2085745.

Almost surely, 2^166856440 is an apocalyptic number.

166856440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166856440 is an abundant number, since it is smaller than the sum of its proper divisors (208570640).

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

166856440 is a wasteful number, since it uses less digits than its factorization.

166856440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4171422 (or 4171418 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 40.

The square root of 166856440 is about 12917.2922859243. The cubic root of 166856440 is about 550.5300015025.

The spelling of 166856440 in words is "one hundred sixty-six million, eight hundred fifty-six thousand, four hundred forty".