21580676489 has 2 divisors, whose sum is σ = 21580676490. Its totient is φ = 21580676488.

The previous prime is 21580676477. The next prime is 21580676519. The reversal of 21580676489 is 98467608512.

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., 13373766025 + 8206910464 = 115645^2 + 90592^2 .

It is a cyclic number.

It is not a de Polignac number, because 21580676489 - 2²⁸ = 21312241033 is a prime.

It is not a weakly prime, because it can be changed into another prime (21580676449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10790338244 + 10790338245.

It is an arithmetic number, because the mean of its divisors is an integer number (10790338245).

Almost surely, 2^21580676489 is an apocalyptic number.

It is an amenable number.

21580676489 is a deficient number, since it is larger than the sum of its proper divisors (1).

21580676489 is an equidigital number, since it uses as much as digits as its factorization.

21580676489 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5806080, while the sum is 56.

The spelling of 21580676489 in words is "twenty-one billion, five hundred eighty million, six hundred seventy-six thousand, four hundred eighty-nine".