21310534405 has 4 divisors (see below), whose sum is σ = 25572641292. Its totient is φ = 17048427520.

The previous prime is 21310534373. The next prime is 21310534439. The reversal of 21310534405 is 50443501312.

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 11368250884 + 9942283521 = 106622^2 + 99711^2 .

It is not a de Polignac number, because 21310534405 - 2⁵ = 21310534373 is a prime.

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, 2131053436 + ... + 2131053445.

It is an arithmetic number, because the mean of its divisors is an integer number (6393160323).

Almost surely, 2^21310534405 is an apocalyptic number.

It is an amenable number.

21310534405 is a deficient number, since it is larger than the sum of its proper divisors (4262106887).

21310534405 is an equidigital number, since it uses as much as digits as its factorization.

21310534405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4262106886.

The product of its (nonzero) digits is 7200, while the sum is 28.

The spelling of 21310534405 in words is "twenty-one billion, three hundred ten million, five hundred thirty-four thousand, four hundred five".