642797117 has 2 divisors, whose sum is σ = 642797118. Its totient is φ = 642797116.

The previous prime is 642797107. The next prime is 642797137. The reversal of 642797117 is 711797246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 585930436 + 56866681 = 24206^2 + 7541^2 .

It is a cyclic number.

It is not a de Polignac number, because 642797117 - 2⁴ = 642797101 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642797107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321398558 + 321398559.

It is an arithmetic number, because the mean of its divisors is an integer number (321398559).

Almost surely, 2^642797117 is an apocalyptic number.

It is an amenable number.

642797117 is a deficient number, since it is larger than the sum of its proper divisors (1).

642797117 is an equidigital number, since it uses as much as digits as its factorization.

642797117 is an evil number, because the sum of its binary digits is even.

The product of its digits is 148176, while the sum is 44.

The square root of 642797117 is about 25353.4438883557. The cubic root of 642797117 is about 863.0275110092.

The spelling of 642797117 in words is "six hundred forty-two million, seven hundred ninety-seven thousand, one hundred seventeen".