20418055631 has 2 divisors, whose sum is σ = 20418055632. Its totient is φ = 20418055630.

The previous prime is 20418055613. The next prime is 20418055661. The reversal of 20418055631 is 13655081402.

Together with previous prime (20418055613) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20418055631 is a prime.

It is a super-2 number, since 2×20418055631² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20418055591 and 20418055600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20418055661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10209027815 + 10209027816.

It is an arithmetic number, because the mean of its divisors is an integer number (10209027816).

Almost surely, 2^20418055631 is an apocalyptic number.

20418055631 is a deficient number, since it is larger than the sum of its proper divisors (1).

20418055631 is an equidigital number, since it uses as much as digits as its factorization.

20418055631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28800, while the sum is 35.

The spelling of 20418055631 in words is "twenty billion, four hundred eighteen million, fifty-five thousand, six hundred thirty-one".