81421624946 has 8 divisors (see below), whose sum is σ = 125433314220. Its totient is φ = 39610520208.

The previous prime is 81421624937. The next prime is 81421624951. The reversal of 81421624946 is 64942612418.

It can be written as a sum of positive squares in 2 ways, for example, as 79558407721 + 1863217225 = 282061^2 + 43165^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 81421624946.

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, 550146041 + ... + 550146188.

Almost surely, 2^81421624946 is an apocalyptic number.

81421624946 is a deficient number, since it is larger than the sum of its proper divisors (44011689274).

81421624946 is a wasteful number, since it uses less digits than its factorization.

81421624946 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1100292268.

The product of its digits is 663552, while the sum is 47.

The spelling of 81421624946 in words is "eighty-one billion, four hundred twenty-one million, six hundred twenty-four thousand, nine hundred forty-six".