21365374513 has 4 divisors (see below), whose sum is σ = 24417570880. Its totient is φ = 18313178148.

The previous prime is 21365374507. The next prime is 21365374519. The reversal of 21365374513 is 31547356312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (21365374507) and next prime (21365374519).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21365374513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21365374519) 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, 1526098173 + ... + 1526098186.

It is an arithmetic number, because the mean of its divisors is an integer number (6104392720).

Almost surely, 2^21365374513 is an apocalyptic number.

It is an amenable number.

21365374513 is a deficient number, since it is larger than the sum of its proper divisors (3052196367).

21365374513 is an equidigital number, since it uses as much as digits as its factorization.

21365374513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3052196366.

The product of its digits is 226800, while the sum is 40.

The spelling of 21365374513 in words is "twenty-one billion, three hundred sixty-five million, three hundred seventy-four thousand, five hundred thirteen".