21751422015 has 64 divisors (see below), whose sum is σ = 37944000000. Its totient is φ = 10598128128.

The previous prime is 21751421981. The next prime is 21751422031. The reversal of 21751422015 is 51022415712.

It is a happy number.

It is not a de Polignac number, because 21751422015 - 2¹¹ = 21751419967 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 12801636 + ... + 12803334.

It is an arithmetic number, because the mean of its divisors is an integer number (592875000).

Almost surely, 2^21751422015 is an apocalyptic number.

21751422015 is a deficient number, since it is larger than the sum of its proper divisors (16192577985).

21751422015 is a wasteful number, since it uses less digits than its factorization.

21751422015 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3304.

The product of its (nonzero) digits is 5600, while the sum is 30.

Adding to 21751422015 its reverse (51022415712), we get a palindrome (72773837727).

The spelling of 21751422015 in words is "twenty-one billion, seven hundred fifty-one million, four hundred twenty-two thousand, fifteen".