161351556 has 48 divisors (see below), whose sum is σ = 399986496. Its totient is φ = 50448384.

The previous prime is 161351549. The next prime is 161351579. The reversal of 161351556 is 655153161.

It is a super-2 number, since 2×161351556² = 52068649247242272, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67575 + ... + 69921.

It is an arithmetic number, because the mean of its divisors is an integer number (8333052).

Almost surely, 2^161351556 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 161351556, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (199993248).

161351556 is an abundant number, since it is smaller than the sum of its proper divisors (238634940).

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

161351556 is a wasteful number, since it uses less digits than its factorization.

161351556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2708 (or 2706 counting only the distinct ones).

The product of its digits is 13500, while the sum is 33.

The square root of 161351556 is about 12702.4232333835. The cubic root of 161351556 is about 544.4078589635.

The spelling of 161351556 in words is "one hundred sixty-one million, three hundred fifty-one thousand, five hundred fifty-six".