21715616612407 has 4 divisors (see below), whose sum is σ = 21718729076976. Its totient is φ = 21712504147840.

The previous prime is 21715616612399. The next prime is 21715616612453. The reversal of 21715616612407 is 70421661651712.

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 21715616612407 - 2³ = 21715616612399 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21715616610407) 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, 1556221819 + ... + 1556235772.

It is an arithmetic number, because the mean of its divisors is an integer number (5429682269244).

Almost surely, 2^{21715616612407} is an apocalyptic number.

21715616612407 is a deficient number, since it is larger than the sum of its proper divisors (3112464569).

21715616612407 is an equidigital number, since it uses as much as digits as its factorization.

21715616612407 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3112464568.

The product of its (nonzero) digits is 846720, while the sum is 49.

The spelling of 21715616612407 in words is "twenty-one trillion, seven hundred fifteen billion, six hundred sixteen million, six hundred twelve thousand, four hundred seven".