20821120431 has 4 divisors (see below), whose sum is σ = 27761493912. Its totient is φ = 13880746952.

The previous prime is 20821120393. The next prime is 20821120433. The reversal of 20821120431 is 13402112802.

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 20821120431 - 2¹⁴ = 20821104047 is a prime.

It is a super-2 number, since 2×20821120431² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20821120433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3470186736 + ... + 3470186741.

It is an arithmetic number, because the mean of its divisors is an integer number (6940373478).

Almost surely, 2^20821120431 is an apocalyptic number.

20821120431 is a deficient number, since it is larger than the sum of its proper divisors (6940373481).

20821120431 is an equidigital number, since it uses as much as digits as its factorization.

20821120431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6940373480.

The product of its (nonzero) digits is 768, while the sum is 24.

The spelling of 20821120431 in words is "twenty billion, eight hundred twenty-one million, one hundred twenty thousand, four hundred thirty-one".