21101011989 has 16 divisors (see below), whose sum is σ = 29309394240. Its totient is φ = 13491616640.

The previous prime is 21101011973. The next prime is 21101011991. The reversal of 21101011989 is 98911010112.

It is a cyclic number.

It is not a de Polignac number, because 21101011989 - 2⁴ = 21101011973 is a prime.

It is a super-2 number, since 2×21101011989² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21101011909) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1446582 + ... + 1461095.

It is an arithmetic number, because the mean of its divisors is an integer number (1831837140).

Almost surely, 2^21101011989 is an apocalyptic number.

It is an amenable number.

21101011989 is a deficient number, since it is larger than the sum of its proper divisors (8208382251).

21101011989 is a wasteful number, since it uses less digits than its factorization.

21101011989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2907780.

The product of its (nonzero) digits is 1296, while the sum is 33.

The spelling of 21101011989 in words is "twenty-one billion, one hundred one million, eleven thousand, nine hundred eighty-nine".