20431187641 has 2 divisors, whose sum is σ = 20431187642. Its totient is φ = 20431187640.

The previous prime is 20431187617. The next prime is 20431187669. The reversal of 20431187641 is 14678113402.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19938569616 + 492618025 = 141204^2 + 22195^2 .

It is a cyclic number.

It is not a de Polignac number, because 20431187641 - 2¹³ = 20431179449 is a prime.

It is a super-2 number, since 2×20431187641² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20431187641.

It is not a weakly prime, because it can be changed into another prime (20431187681) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10215593820 + 10215593821.

It is an arithmetic number, because the mean of its divisors is an integer number (10215593821).

Almost surely, 2^20431187641 is an apocalyptic number.

It is an amenable number.

20431187641 is a deficient number, since it is larger than the sum of its proper divisors (1).

20431187641 is an equidigital number, since it uses as much as digits as its factorization.

20431187641 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32256, while the sum is 37.

The spelling of 20431187641 in words is "twenty billion, four hundred thirty-one million, one hundred eighty-seven thousand, six hundred forty-one".