21222512051 has 4 divisors (see below), whose sum is σ = 22855012992. Its totient is φ = 19590011112.

The previous prime is 21222512041. The next prime is 21222512081. The reversal of 21222512051 is 15021522212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21222512051 - 2¹⁸ = 21222249907 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21222512041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 816250451 + ... + 816250476.

It is an arithmetic number, because the mean of its divisors is an integer number (5713753248).

Almost surely, 2^21222512051 is an apocalyptic number.

21222512051 is a deficient number, since it is larger than the sum of its proper divisors (1632500941).

21222512051 is a wasteful number, since it uses less digits than its factorization.

21222512051 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1632500940.

The product of its (nonzero) digits is 800, while the sum is 23.

The spelling of 21222512051 in words is "twenty-one billion, two hundred twenty-two million, five hundred twelve thousand, fifty-one".