21021101010989 has 2 divisors, whose sum is σ = 21021101010990. Its totient is φ = 21021101010988.

The previous prime is 21021101010953. The next prime is 21021101011019. The reversal of 21021101010989 is 98901010112012.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14877667836964 + 6143433174025 = 3857158^2 + 2478595^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21021101010989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21021101010089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510550505494 + 10510550505495.

It is an arithmetic number, because the mean of its divisors is an integer number (10510550505495).

Almost surely, 2^{21021101010989} is an apocalyptic number.

It is an amenable number.

21021101010989 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021101010989 is an equidigital number, since it uses as much as digits as its factorization.

21021101010989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2592, while the sum is 35.

The spelling of 21021101010989 in words is "twenty-one trillion, twenty-one billion, one hundred one million, ten thousand, nine hundred eighty-nine".