21262564885 has 4 divisors (see below), whose sum is σ = 25515077868. Its totient is φ = 17010051904.

The previous prime is 21262564877. The next prime is 21262564891. The reversal of 21262564885 is 58846526212.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7124879281 + 14137685604 = 84409^2 + 118902^2 .

It is a cyclic number.

It is not a de Polignac number, because 21262564885 - 2³ = 21262564877 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2126256484 + ... + 2126256493.

It is an arithmetic number, because the mean of its divisors is an integer number (6378769467).

Almost surely, 2^21262564885 is an apocalyptic number.

It is an amenable number.

21262564885 is a deficient number, since it is larger than the sum of its proper divisors (4252512983).

21262564885 is an equidigital number, since it uses as much as digits as its factorization.

21262564885 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4252512982.

The product of its digits is 1843200, while the sum is 49.

The spelling of 21262564885 in words is "twenty-one billion, two hundred sixty-two million, five hundred sixty-four thousand, eight hundred eighty-five".