81125988461 has 32 divisors (see below), whose sum is σ = 93978393600. Its totient is φ = 68598316800.

The previous prime is 81125988421. The next prime is 81125988479. The reversal of 81125988461 is 16488952118.

It is a cyclic number.

It is not a de Polignac number, because 81125988461 - 2²² = 81121794157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81125988421) 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, 119831255 + ... + 119831931.

It is an arithmetic number, because the mean of its divisors is an integer number (2936824800).

Almost surely, 2^81125988461 is an apocalyptic number.

It is an amenable number.

81125988461 is a deficient number, since it is larger than the sum of its proper divisors (12852405139).

81125988461 is a wasteful number, since it uses less digits than its factorization.

81125988461 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1485.

The product of its digits is 1105920, while the sum is 53.

The spelling of 81125988461 in words is "eighty-one billion, one hundred twenty-five million, nine hundred eighty-eight thousand, four hundred sixty-one".