21013251089 has 2 divisors, whose sum is σ = 21013251090. Its totient is φ = 21013251088.

The previous prime is 21013251037. The next prime is 21013251121. The reversal of 21013251089 is 98015231012.

It is a happy number.

It is an a-pointer prime, because the next prime (21013251121) can be obtained adding 21013251089 to its sum of digits (32).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21001806400 + 11444689 = 144920^2 + 3383^2 .

It is a cyclic number.

It is not a de Polignac number, because 21013251089 - 2¹⁶ = 21013185553 is a prime.

It is not a weakly prime, because it can be changed into another prime (21013251289) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10506625544 + 10506625545.

It is an arithmetic number, because the mean of its divisors is an integer number (10506625545).

Almost surely, 2^21013251089 is an apocalyptic number.

It is an amenable number.

21013251089 is a deficient number, since it is larger than the sum of its proper divisors (1).

21013251089 is an equidigital number, since it uses as much as digits as its factorization.

21013251089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 32.

The spelling of 21013251089 in words is "twenty-one billion, thirteen million, two hundred fifty-one thousand, eighty-nine".