642634604257 has 2 divisors, whose sum is σ = 642634604258. Its totient is φ = 642634604256.

The previous prime is 642634604207. The next prime is 642634604279. The reversal of 642634604257 is 752406436246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 596533790736 + 46100813521 = 772356^2 + 214711^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642634604257 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 642634604257.

It is not a weakly prime, because it can be changed into another prime (642634604207) 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 as a sum of consecutive naturals, namely, 321317302128 + 321317302129.

It is an arithmetic number, because the mean of its divisors is an integer number (321317302129).

Almost surely, 2^642634604257 is an apocalyptic number.

It is an amenable number.

642634604257 is a deficient number, since it is larger than the sum of its proper divisors (1).

642634604257 is an equidigital number, since it uses as much as digits as its factorization.

642634604257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5806080, while the sum is 49.

The spelling of 642634604257 in words is "six hundred forty-two billion, six hundred thirty-four million, six hundred four thousand, two hundred fifty-seven".