20021313823 has 16 divisors (see below), whose sum is σ = 23639025664. Its totient is φ = 16593893280.

The previous prime is 20021313817. The next prime is 20021313863. The reversal of 20021313823 is 32831312002.

It is a de Polignac number, because none of the positive numbers 2^k-20021313823 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 (20021313863) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 231136 + ... + 305722.

It is an arithmetic number, because the mean of its divisors is an integer number (1477439104).

Almost surely, 2^20021313823 is an apocalyptic number.

20021313823 is a deficient number, since it is larger than the sum of its proper divisors (3617711841).

20021313823 is a wasteful number, since it uses less digits than its factorization.

20021313823 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75862.

The product of its (nonzero) digits is 1728, while the sum is 25.

Adding to 20021313823 its reverse (32831312002), we get a palindrome (52852625825).

The spelling of 20021313823 in words is "twenty billion, twenty-one million, three hundred thirteen thousand, eight hundred twenty-three".