81421624947 has 12 divisors (see below), whose sum is σ = 117555482904. Its totient is φ = 50105615040.

The previous prime is 81421624937. The next prime is 81421624951. The reversal of 81421624947 is 74942612418.

It is not a de Polignac number, because 81421624947 - 2⁷ = 81421624819 is a prime.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 81421624896 and 81421624905.

It is not an unprimeable number, because it can be changed into a prime (81421624937) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 80296954 + ... + 80297967.

It is an arithmetic number, because the mean of its divisors is an integer number (9796290242).

Almost surely, 2^81421624947 is an apocalyptic number.

81421624947 is a deficient number, since it is larger than the sum of its proper divisors (36133857957).

81421624947 is a wasteful number, since it uses less digits than its factorization.

81421624947 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160594950 (or 160594937 counting only the distinct ones).

The product of its digits is 774144, while the sum is 48.

The spelling of 81421624947 in words is "eighty-one billion, four hundred twenty-one million, six hundred twenty-four thousand, nine hundred forty-seven".