21000101111989 has 2 divisors, whose sum is σ = 21000101111990. Its totient is φ = 21000101111988.

The previous prime is 21000101111981. The next prime is 21000101112031. The reversal of 21000101111989 is 98911110100012.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17074729736964 + 3925371375025 = 4132158^2 + 1981255^2 .

It is a cyclic number.

It is not a de Polignac number, because 21000101111989 - 2³ = 21000101111981 is a prime.

It is a super-2 number, since 2×21000101111989² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21000101111981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10500050555994 + 10500050555995.

It is an arithmetic number, because the mean of its divisors is an integer number (10500050555995).

Almost surely, 2^{21000101111989} is an apocalyptic number.

It is an amenable number.

21000101111989 is a deficient number, since it is larger than the sum of its proper divisors (1).

21000101111989 is an equidigital number, since it uses as much as digits as its factorization.

21000101111989 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 34.

The spelling of 21000101111989 in words is "twenty-one trillion, one hundred one million, one hundred eleven thousand, nine hundred eighty-nine".