161131203556 has 12 divisors (see below), whose sum is σ = 288537271792. Its totient is φ = 78691983048.

The previous prime is 161131203487. The next prime is 161131203587. The reversal of 161131203556 is 655302131161.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 468404490 + ... + 468404833.

Almost surely, 2^161131203556 is an apocalyptic number.

It is an amenable number.

161131203556 is a deficient number, since it is larger than the sum of its proper divisors (127406068236).

161131203556 is a wasteful number, since it uses less digits than its factorization.

161131203556 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 936809370 (or 936809368 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 34.

The spelling of 161131203556 in words is "one hundred sixty-one billion, one hundred thirty-one million, two hundred three thousand, five hundred fifty-six".