21589210987 has 2 divisors, whose sum is σ = 21589210988. Its totient is φ = 21589210986.

The previous prime is 21589210963. The next prime is 21589211003. The reversal of 21589210987 is 78901298512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21589210987 - 2²³ = 21580822379 is a prime.

It is not a weakly prime, because it can be changed into another prime (21589210927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10794605493 + 10794605494.

It is an arithmetic number, because the mean of its divisors is an integer number (10794605494).

Almost surely, 2^21589210987 is an apocalyptic number.

21589210987 is a deficient number, since it is larger than the sum of its proper divisors (1).

21589210987 is an equidigital number, since it uses as much as digits as its factorization.

21589210987 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 725760, while the sum is 52.

The spelling of 21589210987 in words is "twenty-one billion, five hundred eighty-nine million, two hundred ten thousand, nine hundred eighty-seven".