20720023831 has 4 divisors (see below), whose sum is σ = 22313871832. Its totient is φ = 19126175832.

The previous prime is 20720023801. The next prime is 20720023843. The reversal of 20720023831 is 13832002702.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20720023831 - 2¹⁷ = 20719892759 is a prime.

It is a super-2 number, since 2×20720023831² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20720023831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20720023801) 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, 796923981 + ... + 796924006.

It is an arithmetic number, because the mean of its divisors is an integer number (5578467958).

Almost surely, 2^20720023831 is an apocalyptic number.

20720023831 is a deficient number, since it is larger than the sum of its proper divisors (1593848001).

20720023831 is a wasteful number, since it uses less digits than its factorization.

20720023831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1593848000.

The product of its (nonzero) digits is 4032, while the sum is 28.

The spelling of 20720023831 in words is "twenty billion, seven hundred twenty million, twenty-three thousand, eight hundred thirty-one".