161557240 has 48 divisors (see below), whose sum is σ = 393633000. Its totient is φ = 59649408.

The previous prime is 161557237. The next prime is 161557241. The reversal of 161557240 is 42755161.

It is a super-2 number, since 2×161557240² = 52201483592835200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161557241) 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 11 ways as a sum of consecutive naturals, for example, 5190 + ... + 18709.

Almost surely, 2^161557240 is an apocalyptic number.

161557240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161557240 is an abundant number, since it is smaller than the sum of its proper divisors (232075760).

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

161557240 is a wasteful number, since it uses less digits than its factorization.

161557240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23936 (or 23919 counting only the distinct ones).

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 161557240 is about 12710.5169053033. The cubic root of 161557240 is about 544.6390899513.

The spelling of 161557240 in words is "one hundred sixty-one million, five hundred fifty-seven thousand, two hundred forty".