81401382765131 has 32 divisors (see below), whose sum is σ = 101291601600000. Its totient is φ = 64269241735680.

The previous prime is 81401382765127. The next prime is 81401382765139. The reversal of 81401382765131 is 13156728310418.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 81401382765131 - 2² = 81401382765127 is a prime.

It is a super-2 number, since 2×81401382765131² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 81401382765131.

It is not an unprimeable number, because it can be changed into a prime (81401382765139) 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, 1707920 + ... + 12873218.

It is an arithmetic number, because the mean of its divisors is an integer number (3165362550000).

Almost surely, 2^{81401382765131} is an apocalyptic number.

81401382765131 is a deficient number, since it is larger than the sum of its proper divisors (19890218834869).

81401382765131 is a wasteful number, since it uses less digits than its factorization.

81401382765131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11168339.

The product of its (nonzero) digits is 967680, while the sum is 50.

The spelling of 81401382765131 in words is "eighty-one trillion, four hundred one billion, three hundred eighty-two million, seven hundred sixty-five thousand, one hundred thirty-one".