21320371365 has 16 divisors (see below), whose sum is σ = 35213001216. Its totient is φ = 11004062400.

The previous prime is 21320371343. The next prime is 21320371379. The reversal of 21320371365 is 56317302312.

It is not a de Polignac number, because 21320371365 - 2⁶ = 21320371301 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22924666 + ... + 22925595.

It is an arithmetic number, because the mean of its divisors is an integer number (2200812576).

Almost surely, 2^21320371365 is an apocalyptic number.

It is an amenable number.

21320371365 is a deficient number, since it is larger than the sum of its proper divisors (13892629851).

21320371365 is a wasteful number, since it uses less digits than its factorization.

21320371365 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45850300.

The product of its (nonzero) digits is 22680, while the sum is 33.

Adding to 21320371365 its reverse (56317302312), we get a palindrome (77637673677).

The spelling of 21320371365 in words is "twenty-one billion, three hundred twenty million, three hundred seventy-one thousand, three hundred sixty-five".