21102025639 has 2 divisors, whose sum is σ = 21102025640. Its totient is φ = 21102025638.

The previous prime is 21102025627. The next prime is 21102025661. The reversal of 21102025639 is 93652020112.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21102025639 - 2¹⁵ = 21101992871 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21102025639.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21102025619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10551012819 + 10551012820.

It is an arithmetic number, because the mean of its divisors is an integer number (10551012820).

Almost surely, 2^21102025639 is an apocalyptic number.

21102025639 is a deficient number, since it is larger than the sum of its proper divisors (1).

21102025639 is an equidigital number, since it uses as much as digits as its factorization.

21102025639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6480, while the sum is 31.

The spelling of 21102025639 in words is "twenty-one billion, one hundred two million, twenty-five thousand, six hundred thirty-nine".