81632775601 has 4 divisors (see below), whose sum is σ = 87912219892. Its totient is φ = 75353331312.

The previous prime is 81632775583. The next prime is 81632775607. The reversal of 81632775601 is 10657723618.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5788166400 + 75844609201 = 76080^2 + 275399^2 .

It is a cyclic number.

It is not a de Polignac number, because 81632775601 - 2¹³ = 81632767409 is a prime.

It is a super-2 number, since 2×81632775601² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81632775607) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3139722126 + ... + 3139722151.

It is an arithmetic number, because the mean of its divisors is an integer number (21978054973).

Almost surely, 2^81632775601 is an apocalyptic number.

It is an amenable number.

81632775601 is a deficient number, since it is larger than the sum of its proper divisors (6279444291).

81632775601 is a wasteful number, since it uses less digits than its factorization.

81632775601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6279444290.

The product of its (nonzero) digits is 423360, while the sum is 46.

The spelling of 81632775601 in words is "eighty-one billion, six hundred thirty-two million, seven hundred seventy-five thousand, six hundred one".