21502676641 has 2 divisors, whose sum is σ = 21502676642. Its totient is φ = 21502676640.

The previous prime is 21502676639. The next prime is 21502676659. The reversal of 21502676641 is 14667620512.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17510964241 + 3991712400 = 132329^2 + 63180^2 .

It is a cyclic number.

It is not a de Polignac number, because 21502676641 - 2¹ = 21502676639 is a prime.

Together with 21502676639, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21502676594 and 21502676603.

It is not a weakly prime, because it can be changed into another prime (21502670641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10751338320 + 10751338321.

It is an arithmetic number, because the mean of its divisors is an integer number (10751338321).

Almost surely, 2^21502676641 is an apocalyptic number.

It is an amenable number.

21502676641 is a deficient number, since it is larger than the sum of its proper divisors (1).

21502676641 is an equidigital number, since it uses as much as digits as its factorization.

21502676641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 40.

The spelling of 21502676641 in words is "twenty-one billion, five hundred two million, six hundred seventy-six thousand, six hundred forty-one".