81028081923 has 4 divisors (see below), whose sum is σ = 108037442568. Its totient is φ = 54018721280.

The previous prime is 81028081913. The next prime is 81028081931. The reversal of 81028081923 is 32918082018.

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 81028081923 - 2⁴ = 81028081907 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81028081913) 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, 13504680318 + ... + 13504680323.

It is an arithmetic number, because the mean of its divisors is an integer number (27009360642).

Almost surely, 2^81028081923 is an apocalyptic number.

81028081923 is a deficient number, since it is larger than the sum of its proper divisors (27009360645).

81028081923 is a wasteful number, since it uses less digits than its factorization.

81028081923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27009360644.

The product of its (nonzero) digits is 55296, while the sum is 42.

The spelling of 81028081923 in words is "eighty-one billion, twenty-eight million, eighty-one thousand, nine hundred twenty-three".