21023604364765 has 32 divisors (see below), whose sum is σ = 25907255934336. Its totient is φ = 16368301962240.

The previous prime is 21023604364757. The next prime is 21023604364769. The reversal of 21023604364765 is 56746340632012.

It is not a de Polignac number, because 21023604364765 - 2³ = 21023604364757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21023604364769) 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, 367497654 + ... + 367554856.

It is an arithmetic number, because the mean of its divisors is an integer number (809601747948).

Almost surely, 2^{21023604364765} is an apocalyptic number.

It is an amenable number.

21023604364765 is a deficient number, since it is larger than the sum of its proper divisors (4883651569571).

21023604364765 is a wasteful number, since it uses less digits than its factorization.

21023604364765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61629.

The product of its (nonzero) digits is 4354560, while the sum is 49.

Adding to 21023604364765 its reverse (56746340632012), we get a palindrome (77769944996777).

The spelling of 21023604364765 in words is "twenty-one trillion, twenty-three billion, six hundred four million, three hundred sixty-four thousand, seven hundred sixty-five".