161731009456 has 20 divisors (see below), whose sum is σ = 313477325800. Its totient is φ = 80833635072.

The previous prime is 161731009409. The next prime is 161731009463. The reversal of 161731009456 is 654900137161.

It is a super-2 number, since 2×161731009456² (a number of 23 digits) contains 22 as substring.

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, 1949961 + ... + 2031208.

It is an arithmetic number, because the mean of its divisors is an integer number (15673866290).

Almost surely, 2^161731009456 is an apocalyptic number.

161731009456 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

161731009456 is a deficient number, since it is larger than the sum of its proper divisors (151746316344).

161731009456 is a wasteful number, since it uses less digits than its factorization.

161731009456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3983716 (or 3983710 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 43.

The spelling of 161731009456 in words is "one hundred sixty-one billion, seven hundred thirty-one million, nine thousand, four hundred fifty-six".