81165437640001 has 64 divisors (see below), whose sum is σ = 99813882470400. Its totient is φ = 64988433216000.

The previous prime is 81165437639977. The next prime is 81165437640017. The reversal of 81165437640001 is 10004673456118.

It is a cyclic number.

It is not a de Polignac number, because 81165437640001 - 2⁷ = 81165437639873 is a prime.

It is a super-2 number, since 2×81165437640001² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81165437640101) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 974345050 + ... + 974428348.

It is an arithmetic number, because the mean of its divisors is an integer number (1559591913600).

Almost surely, 2^{81165437640001} is an apocalyptic number.

It is an amenable number.

81165437640001 is a deficient number, since it is larger than the sum of its proper divisors (18648444830399).

81165437640001 is a wasteful number, since it uses less digits than its factorization.

81165437640001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86438.

The product of its (nonzero) digits is 483840, while the sum is 46.

The spelling of 81165437640001 in words is "eighty-one trillion, one hundred sixty-five billion, four hundred thirty-seven million, six hundred forty thousand, one".