81421624945 has 16 divisors (see below), whose sum is σ = 98192736000. Its totient is φ = 64813211008.

The previous prime is 81421624937. The next prime is 81421624951. The reversal of 81421624945 is 54942612418.

It is a cyclic number.

It is not a de Polignac number, because 81421624945 - 2³ = 81421624937 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 81421624895 and 81421624904.

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, 1513926 + ... + 1566784.

It is an arithmetic number, because the mean of its divisors is an integer number (6137046000).

Almost surely, 2^81421624945 is an apocalyptic number.

It is an amenable number.

81421624945 is a deficient number, since it is larger than the sum of its proper divisors (16771111055).

81421624945 is a wasteful number, since it uses less digits than its factorization.

81421624945 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54392.

The product of its digits is 552960, while the sum is 46.

The spelling of 81421624945 in words is "eighty-one billion, four hundred twenty-one million, six hundred twenty-four thousand, nine hundred forty-five".