21326011639 has 2 divisors, whose sum is σ = 21326011640. Its totient is φ = 21326011638.

The previous prime is 21326011621. The next prime is 21326011661. The reversal of 21326011639 is 93611062312.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21326011639 - 2¹¹ = 21326009591 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21326011139) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10663005819 + 10663005820.

It is an arithmetic number, because the mean of its divisors is an integer number (10663005820).

Almost surely, 2^21326011639 is an apocalyptic number.

21326011639 is a deficient number, since it is larger than the sum of its proper divisors (1).

21326011639 is an equidigital number, since it uses as much as digits as its factorization.

21326011639 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11664, while the sum is 34.

The spelling of 21326011639 in words is "twenty-one billion, three hundred twenty-six million, eleven thousand, six hundred thirty-nine".