20989924641 has 27 divisors (see below), whose sum is σ = 35273897841. Its totient is φ = 11992504104.

The previous prime is 20989924603. The next prime is 20989924661. The reversal of 20989924641 is 14642998902.

The square root of 20989924641 is 144879.

It is a perfect power (a square), and thus also a powerful number.

20989924641 is a `hidden beast` number, since 2 + 0 + 98 + 9 + 92 + 464 + 1 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-20989924641 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20989924601) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 3039010 + ... + 3045908.

Almost surely, 2^20989924641 is an apocalyptic number.

20989924641 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20989924641 is the 144879-th square number.

20989924641 is the 72440-th centered octagonal number.

It is an amenable number.

20989924641 is a deficient number, since it is larger than the sum of its proper divisors (14283973200).

20989924641 is an frugal number, since it uses more digits than its factorization.

20989924641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13818 (or 6909 counting only the distinct ones).

The product of its (nonzero) digits is 2239488, while the sum is 54.

The spelling of 20989924641 in words is "twenty billion, nine hundred eighty-nine million, nine hundred twenty-four thousand, six hundred forty-one".