81925934839 has 4 divisors (see below), whose sum is σ = 93629639824. Its totient is φ = 70222229856.

The previous prime is 81925934813. The next prime is 81925934879. The reversal of 81925934839 is 93843952918.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81925934839 - 2¹⁹ = 81925410551 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81925934809) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5851852482 + ... + 5851852495.

It is an arithmetic number, because the mean of its divisors is an integer number (23407409956).

Almost surely, 2^81925934839 is an apocalyptic number.

81925934839 is a deficient number, since it is larger than the sum of its proper divisors (11703704985).

81925934839 is a wasteful number, since it uses less digits than its factorization.

81925934839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11703704984.

The product of its digits is 16796160, while the sum is 61.

The spelling of 81925934839 in words is "eighty-one billion, nine hundred twenty-five million, nine hundred thirty-four thousand, eight hundred thirty-nine".