642618345631 has 2 divisors, whose sum is σ = 642618345632. Its totient is φ = 642618345630.

The previous prime is 642618345599. The next prime is 642618345637. The reversal of 642618345631 is 136543816246.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 642618345631 - 2⁵ = 642618345599 is a prime.

It is a super-2 number, since 2×642618345631² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642618345637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321309172815 + 321309172816.

It is an arithmetic number, because the mean of its divisors is an integer number (321309172816).

Almost surely, 2^642618345631 is an apocalyptic number.

642618345631 is a deficient number, since it is larger than the sum of its proper divisors (1).

642618345631 is an equidigital number, since it uses as much as digits as its factorization.

642618345631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2488320, while the sum is 49.

The spelling of 642618345631 in words is "six hundred forty-two billion, six hundred eighteen million, three hundred forty-five thousand, six hundred thirty-one".