21707511427 has 4 divisors (see below), whose sum is σ = 24808584496. Its totient is φ = 18606438360.

The previous prime is 21707511409. The next prime is 21707511431. The reversal of 21707511427 is 72411570712.

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 21707511427 - 2⁷ = 21707511299 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21707511437) 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, 1550536524 + ... + 1550536537.

It is an arithmetic number, because the mean of its divisors is an integer number (6202146124).

Almost surely, 2^21707511427 is an apocalyptic number.

21707511427 is a deficient number, since it is larger than the sum of its proper divisors (3101073069).

21707511427 is an equidigital number, since it uses as much as digits as its factorization.

21707511427 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3101073068.

The product of its (nonzero) digits is 27440, while the sum is 37.

The spelling of 21707511427 in words is "twenty-one billion, seven hundred seven million, five hundred eleven thousand, four hundred twenty-seven".