81630161553 has 32 divisors (see below), whose sum is σ = 119728627200. Its totient is φ = 49240303616.

The previous prime is 81630161549. The next prime is 81630161579. The reversal of 81630161553 is 35516103618.

It is not a de Polignac number, because 81630161553 - 2² = 81630161549 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81630161513) 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, 226168 + ... + 463046.

It is an arithmetic number, because the mean of its divisors is an integer number (3741519600).

Almost surely, 2^81630161553 is an apocalyptic number.

It is an amenable number.

81630161553 is a deficient number, since it is larger than the sum of its proper divisors (38098465647).

81630161553 is a wasteful number, since it uses less digits than its factorization.

81630161553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 237161.

The product of its (nonzero) digits is 64800, while the sum is 39.

The spelling of 81630161553 in words is "eighty-one billion, six hundred thirty million, one hundred sixty-one thousand, five hundred fifty-three".