21365564434375 has 24 divisors (see below), whose sum is σ = 30520281514464. Its totient is φ = 14650672740000.

The previous prime is 21365564434363. The next prime is 21365564434387. The reversal of 21365564434375 is 57343446556312.

It is an interprime number because it is at equal distance from previous prime (21365564434363) and next prime (21365564434387).

It is not a de Polignac number, because 21365564434375 - 2³⁹ = 20815808620487 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 488333884 + ... + 488377633.

It is an arithmetic number, because the mean of its divisors is an integer number (1271678396436).

Almost surely, 2^{21365564434375} is an apocalyptic number.

21365564434375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21365564434375 is a deficient number, since it is larger than the sum of its proper divisors (9154717080089).

21365564434375 is an frugal number, since it uses more digits than its factorization.

21365564434375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 976711549 (or 976711529 counting only the distinct ones).

The product of its digits is 108864000, while the sum is 58.

The spelling of 21365564434375 in words is "twenty-one trillion, three hundred sixty-five billion, five hundred sixty-four million, four hundred thirty-four thousand, three hundred seventy-five".