20400231431 has 4 divisors (see below), whose sum is σ = 20785141512. Its totient is φ = 20015321352.

The previous prime is 20400231329. The next prime is 20400231437. The reversal of 20400231431 is 13413200402.

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 20400231431 - 2¹⁸ = 20399969287 is a prime.

It is a super-2 number, since 2×20400231431² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20400231437) 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, 192454961 + ... + 192455066.

It is an arithmetic number, because the mean of its divisors is an integer number (5196285378).

Almost surely, 2^20400231431 is an apocalyptic number.

20400231431 is a deficient number, since it is larger than the sum of its proper divisors (384910081).

20400231431 is an equidigital number, since it uses as much as digits as its factorization.

20400231431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 384910080.

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 20400231431 its reverse (13413200402), we get a palindrome (33813431833).

The spelling of 20400231431 in words is "twenty billion, four hundred million, two hundred thirty-one thousand, four hundred thirty-one".