165956440 has 32 divisors (see below), whose sum is σ = 402126480. Its totient is φ = 61276032.

The previous prime is 165956437. The next prime is 165956443. The reversal of 165956440 is 44659561.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (165956437) and next prime (165956443).

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 165956393 and 165956402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165956443) 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, 159054 + ... + 160093.

Almost surely, 2^165956440 is an apocalyptic number.

165956440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

165956440 is an abundant number, since it is smaller than the sum of its proper divisors (236170040).

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

165956440 is a wasteful number, since it uses less digits than its factorization.

165956440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319171 (or 319167 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 40.

The square root of 165956440 is about 12882.4081599676. The cubic root of 165956440 is about 549.5383895420.

The spelling of 165956440 in words is "one hundred sixty-five million, nine hundred fifty-six thousand, four hundred forty".