81491134364 has 12 divisors (see below), whose sum is σ = 147527053800. Its totient is φ = 39340547568.

The previous prime is 81491134321. The next prime is 81491134379. The reversal of 81491134364 is 46343119418.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 351254774 + ... + 351255005.

It is an arithmetic number, because the mean of its divisors is an integer number (12293921150).

Almost surely, 2^81491134364 is an apocalyptic number.

It is an amenable number.

81491134364 is a deficient number, since it is larger than the sum of its proper divisors (66035919436).

81491134364 is a wasteful number, since it uses less digits than its factorization.

81491134364 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 702509812 (or 702509810 counting only the distinct ones).

The product of its digits is 248832, while the sum is 44.

The spelling of 81491134364 in words is "eighty-one billion, four hundred ninety-one million, one hundred thirty-four thousand, three hundred sixty-four".