21591000937 has 4 divisors (see below), whose sum is σ = 23553819216. Its totient is φ = 19628182660.

The previous prime is 21591000919. The next prime is 21591000967. The reversal of 21591000937 is 73900019512.

It is the 59988-th star number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21591000937 - 2¹⁵ = 21590968169 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21591000896 and 21591000905.

It is not an unprimeable number, because it can be changed into a prime (21591000967) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 981409123 + ... + 981409144.

It is an arithmetic number, because the mean of its divisors is an integer number (5888454804).

Almost surely, 2^21591000937 is an apocalyptic number.

It is an amenable number.

21591000937 is a deficient number, since it is larger than the sum of its proper divisors (1962818279).

21591000937 is a wasteful number, since it uses less digits than its factorization.

21591000937 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1962818278.

The product of its (nonzero) digits is 17010, while the sum is 37.

The spelling of 21591000937 in words is "twenty-one billion, five hundred ninety-one million, nine hundred thirty-seven", and thus it is an aban number.