21073097591 has 32 divisors (see below), whose sum is σ = 26604695040. Its totient is φ = 16245339264.

The previous prime is 21073097587. The next prime is 21073097597. The reversal of 21073097591 is 19579037012.

It is not a de Polignac number, because 21073097591 - 2² = 21073097587 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21073097597) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1633121 + ... + 1645973.

It is an arithmetic number, because the mean of its divisors is an integer number (831396720).

Almost surely, 2^21073097591 is an apocalyptic number.

21073097591 is a deficient number, since it is larger than the sum of its proper divisors (5531597449).

21073097591 is a wasteful number, since it uses less digits than its factorization.

21073097591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13335.

The product of its (nonzero) digits is 119070, while the sum is 44.

The spelling of 21073097591 in words is "twenty-one billion, seventy-three million, ninety-seven thousand, five hundred ninety-one".