21501039393 has 6 divisors (see below), whose sum is σ = 31057056914. Its totient is φ = 14334026256.

The previous prime is 21501039389. The next prime is 21501039397. The reversal of 21501039393 is 39393010512.

It is an interprime number because it is at equal distance from previous prime (21501039389) and next prime (21501039397).

It can be written as a sum of positive squares in only one way, i.e., 16873230609 + 4627808784 = 129897^2 + 68028^2 .

It is not a de Polignac number, because 21501039393 - 2² = 21501039389 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21501039397) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1194502180 + ... + 1194502197.

Almost surely, 2^21501039393 is an apocalyptic number.

It is an amenable number.

21501039393 is a deficient number, since it is larger than the sum of its proper divisors (9556017521).

21501039393 is a wasteful number, since it uses less digits than its factorization.

21501039393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2389004383 (or 2389004380 counting only the distinct ones).

The product of its (nonzero) digits is 21870, while the sum is 36.

The spelling of 21501039393 in words is "twenty-one billion, five hundred one million, thirty-nine thousand, three hundred ninety-three".