81630161571 has 32 divisors (see below), whose sum is σ = 127929231360. Its totient is φ = 45321676416.

The previous prime is 81630161549. The next prime is 81630161579. The reversal of 81630161571 is 17516103618.

It is not a de Polignac number, because 81630161571 - 2²³ = 81621772963 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81630161579) 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, 485605 + ... + 631721.

It is an arithmetic number, because the mean of its divisors is an integer number (3997788480).

Almost surely, 2^81630161571 is an apocalyptic number.

81630161571 is a deficient number, since it is larger than the sum of its proper divisors (46299069789).

81630161571 is a wasteful number, since it uses less digits than its factorization.

81630161571 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 146883.

The product of its (nonzero) digits is 30240, while the sum is 39.

The spelling of 81630161571 in words is "eighty-one billion, six hundred thirty million, one hundred sixty-one thousand, five hundred seventy-one".