20731754021 has 4 divisors (see below), whose sum is σ = 22616458944. Its totient is φ = 18847049100.

The previous prime is 20731754011. The next prime is 20731754039. The reversal of 20731754021 is 12045713702.

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 not a de Polignac number, because 20731754021 - 2¹⁰ = 20731752997 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20731754011) 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 3 ways as a sum of consecutive naturals, for example, 942352445 + ... + 942352466.

It is an arithmetic number, because the mean of its divisors is an integer number (5654114736).

Almost surely, 2^20731754021 is an apocalyptic number.

It is an amenable number.

20731754021 is a deficient number, since it is larger than the sum of its proper divisors (1884704923).

20731754021 is a wasteful number, since it uses less digits than its factorization.

20731754021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1884704922.

The product of its (nonzero) digits is 11760, while the sum is 32.

The spelling of 20731754021 in words is "twenty billion, seven hundred thirty-one million, seven hundred fifty-four thousand, twenty-one".