21015130751 has 16 divisors (see below), whose sum is σ = 22021639680. Its totient is φ = 20016516960.

The previous prime is 21015130739. The next prime is 21015130769. The reversal of 21015130751 is 15703151012.

It is a cyclic number.

It is not a de Polignac number, because 21015130751 - 2³⁰ = 19941388927 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21015130751.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21015130651) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11745965 + ... + 11747753.

It is an arithmetic number, because the mean of its divisors is an integer number (1376352480).

Almost surely, 2^21015130751 is an apocalyptic number.

21015130751 is a deficient number, since it is larger than the sum of its proper divisors (1006508929).

21015130751 is a wasteful number, since it uses less digits than its factorization.

21015130751 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3686.

The product of its (nonzero) digits is 1050, while the sum is 26.

Adding to 21015130751 its reverse (15703151012), we get a palindrome (36718281763).

The spelling of 21015130751 in words is "twenty-one billion, fifteen million, one hundred thirty thousand, seven hundred fifty-one".