81381255074 has 48 divisors (see below), whose sum is σ = 146883514752. Its totient is φ = 33064356864.

The previous prime is 81381255013. The next prime is 81381255077. The reversal of 81381255074 is 47055218318.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81381255077) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4101722 + ... + 4121514.

It is an arithmetic number, because the mean of its divisors is an integer number (3060073224).

Almost surely, 2^81381255074 is an apocalyptic number.

81381255074 is a deficient number, since it is larger than the sum of its proper divisors (65502259678).

81381255074 is a wasteful number, since it uses less digits than its factorization.

81381255074 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20051 (or 19938 counting only the distinct ones).

The product of its (nonzero) digits is 268800, while the sum is 44.

The spelling of 81381255074 in words is "eighty-one billion, three hundred eighty-one million, two hundred fifty-five thousand, seventy-four".