21864875051 has 4 divisors (see below), whose sum is σ = 22090286232. Its totient is φ = 21639463872.

The previous prime is 21864875027. The next prime is 21864875063. The reversal of 21864875051 is 15057846812.

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 21864875051 - 2¹⁸ = 21864612907 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21864874987 and 21864875005.

It is not an unprimeable number, because it can be changed into a prime (21864878051) 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, 112705445 + ... + 112705638.

It is an arithmetic number, because the mean of its divisors is an integer number (5522571558).

Almost surely, 2^21864875051 is an apocalyptic number.

21864875051 is a deficient number, since it is larger than the sum of its proper divisors (225411181).

21864875051 is an equidigital number, since it uses as much as digits as its factorization.

21864875051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 225411180.

The product of its (nonzero) digits is 537600, while the sum is 47.

The spelling of 21864875051 in words is "twenty-one billion, eight hundred sixty-four million, eight hundred seventy-five thousand, fifty-one".