21391323027 has 16 divisors (see below), whose sum is σ = 28641634560. Its totient is φ = 14200991072.

The previous prime is 21391323017. The next prime is 21391323059. The reversal of 21391323027 is 72032319312.

It is a cyclic number.

It is not a de Polignac number, because 21391323027 - 2⁷ = 21391322899 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21391323007) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3110749 + ... + 3117617.

It is an arithmetic number, because the mean of its divisors is an integer number (1790102160).

Almost surely, 2^21391323027 is an apocalyptic number.

21391323027 is a deficient number, since it is larger than the sum of its proper divisors (7250311533).

21391323027 is a wasteful number, since it uses less digits than its factorization.

21391323027 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11082.

The product of its (nonzero) digits is 13608, while the sum is 33.

The spelling of 21391323027 in words is "twenty-one billion, three hundred ninety-one million, three hundred twenty-three thousand, twenty-seven".