161561056 has 12 divisors (see below), whose sum is σ = 318073392. Its totient is φ = 80780512.

The previous prime is 161561051. The next prime is 161561087. The reversal of 161561056 is 650165161.

It is a super-2 number, since 2×161561056² = 52203949631670272, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161561051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2524360 + ... + 2524423.

It is an arithmetic number, because the mean of its divisors is an integer number (26506116).

Almost surely, 2^161561056 is an apocalyptic number.

161561056 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

161561056 is a deficient number, since it is larger than the sum of its proper divisors (156512336).

161561056 is an equidigital number, since it uses as much as digits as its factorization.

161561056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5048793 (or 5048785 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 31.

The square root of 161561056 is about 12710.6670163292. The cubic root of 161561056 is about 544.6433780628.

The spelling of 161561056 in words is "one hundred sixty-one million, five hundred sixty-one thousand, fifty-six".