81425387994 has 32 divisors (see below), whose sum is σ = 167748599616. Its totient is φ = 26329847040.

The previous prime is 81425387947. The next prime is 81425388017. The reversal of 81425387994 is 49978352418.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 469372 + ... + 618999.

It is an arithmetic number, because the mean of its divisors is an integer number (5242143738).

Almost surely, 2^81425387994 is an apocalyptic number.

81425387994 is an abundant number, since it is smaller than the sum of its proper divisors (86323211622).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81425387994 is a wasteful number, since it uses less digits than its factorization.

81425387994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1088750.

The product of its digits is 17418240, while the sum is 60.

The spelling of 81425387994 in words is "eighty-one billion, four hundred twenty-five million, three hundred eighty-seven thousand, nine hundred ninety-four".