21532765679 has 2 divisors, whose sum is σ = 21532765680. Its totient is φ = 21532765678.

The previous prime is 21532765673. The next prime is 21532765693. The reversal of 21532765679 is 97656723512.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21532765679 - 2¹² = 21532761583 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21532765679.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21532765673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10766382839 + 10766382840.

It is an arithmetic number, because the mean of its divisors is an integer number (10766382840).

Almost surely, 2^21532765679 is an apocalyptic number.

21532765679 is a deficient number, since it is larger than the sum of its proper divisors (1).

21532765679 is an equidigital number, since it uses as much as digits as its factorization.

21532765679 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4762800, while the sum is 53.

The spelling of 21532765679 in words is "twenty-one billion, five hundred thirty-two million, seven hundred sixty-five thousand, six hundred seventy-nine".