21020131310989 has 2 divisors, whose sum is σ = 21020131310990. Its totient is φ = 21020131310988.

The previous prime is 21020131310933. The next prime is 21020131311013. The reversal of 21020131310989 is 98901313102012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20896628266089 + 123503044900 = 4571283^2 + 351430^2 .

It is a cyclic number.

It is not a de Polignac number, because 21020131310989 - 2⁷ = 21020131310861 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21020131313989) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510065655494 + 10510065655495.

It is an arithmetic number, because the mean of its divisors is an integer number (10510065655495).

Almost surely, 2^{21020131310989} is an apocalyptic number.

It is an amenable number.

21020131310989 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020131310989 is an equidigital number, since it uses as much as digits as its factorization.

21020131310989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 23328, while the sum is 40.

The spelling of 21020131310989 in words is "twenty-one trillion, twenty billion, one hundred thirty-one million, three hundred ten thousand, nine hundred eighty-nine".