1021100021989 has 2 divisors, whose sum is σ = 1021100021990. Its totient is φ = 1021100021988.

The previous prime is 1021100021957. The next prime is 1021100022011. The reversal of 1021100021989 is 9891200011201.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 994058850625 + 27041171364 = 997025^2 + 164442^2 .

It is a cyclic number.

It is not a de Polignac number, because 1021100021989 - 2⁵ = 1021100021957 is a prime.

It is a super-2 number, since 2×1021100021989² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1021100021789) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 510550010994 + 510550010995.

It is an arithmetic number, because the mean of its divisors is an integer number (510550010995).

Almost surely, 2^{1021100021989} is an apocalyptic number.

It is an amenable number.

1021100021989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1021100021989 is an equidigital number, since it uses as much as digits as its factorization.

1021100021989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 34.

The spelling of 1021100021989 in words is "one trillion, twenty-one billion, one hundred million, twenty-one thousand, nine hundred eighty-nine".