161887400031 has 32 divisors (see below), whose sum is σ = 255223987200. Its totient is φ = 89305977600.

The previous prime is 161887399967. The next prime is 161887400083. The reversal of 161887400031 is 130004788161.

It is not a de Polignac number, because 161887400031 - 2⁶ = 161887399967 is a prime.

It is a super-2 number, since 2×161887400031² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161887400431) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 8003731 + ... + 8023931.

It is an arithmetic number, because the mean of its divisors is an integer number (7975749600).

Almost surely, 2^161887400031 is an apocalyptic number.

161887400031 is a deficient number, since it is larger than the sum of its proper divisors (93336587169).

161887400031 is a wasteful number, since it uses less digits than its factorization.

161887400031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33399.

The product of its (nonzero) digits is 32256, while the sum is 39.

The spelling of 161887400031 in words is "one hundred sixty-one billion, eight hundred eighty-seven million, four hundred thousand, thirty-one".