161659440 has 60 divisors (see below), whose sum is σ = 542908704. Its totient is φ = 43108992.

The previous prime is 161659417. The next prime is 161659447. The reversal of 161659440 is 44956161.

161659440 is a `hidden beast` number, since 1 + 61 + 6 + 594 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (60).

It is a super-2 number, since 2×161659440² = 52267549082227200, which contains 22 as substring.

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 = 161659395 and 161659404.

It is not an unprimeable number, because it can be changed into a prime (161659447) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 111544 + ... + 112983.

Almost surely, 2^161659440 is an apocalyptic number.

161659440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161659440 is an abundant number, since it is smaller than the sum of its proper divisors (381249264).

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

161659440 is a wasteful number, since it uses less digits than its factorization.

161659440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224546 (or 224537 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 161659440 is about 12714.5365625335. The cubic root of 161659440 is about 544.7539107252.

The spelling of 161659440 in words is "one hundred sixty-one million, six hundred fifty-nine thousand, four hundred forty".