20100021989 has 4 divisors (see below), whose sum is σ = 20102154624. Its totient is φ = 20097889356.

The previous prime is 20100021983. The next prime is 20100022009. The reversal of 20100021989 is 98912000102.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20100021989 - 2⁴ = 20100021973 is a prime.

It is a super-2 number, since 2×20100021989² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20100021983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1052117 + ... + 1071050.

It is an arithmetic number, because the mean of its divisors is an integer number (5025538656).

Almost surely, 2^20100021989 is an apocalyptic number.

It is an amenable number.

20100021989 is a deficient number, since it is larger than the sum of its proper divisors (2132635).

20100021989 is an equidigital number, since it uses as much as digits as its factorization.

20100021989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2132634.

The product of its (nonzero) digits is 2592, while the sum is 32.

The spelling of 20100021989 in words is "twenty billion, one hundred million, twenty-one thousand, nine hundred eighty-nine".