642017693 has 2 divisors, whose sum is σ = 642017694. Its totient is φ = 642017692.

The previous prime is 642017687. The next prime is 642017707. The reversal of 642017693 is 396710246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 601083289 + 40934404 = 24517^2 + 6398^2 .

It is a cyclic number.

It is not a de Polignac number, because 642017693 - 2²⁰ = 640969117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642017633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321008846 + 321008847.

It is an arithmetic number, because the mean of its divisors is an integer number (321008847).

Almost surely, 2^642017693 is an apocalyptic number.

It is an amenable number.

642017693 is a deficient number, since it is larger than the sum of its proper divisors (1).

642017693 is an equidigital number, since it uses as much as digits as its factorization.

642017693 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54432, while the sum is 38.

The square root of 642017693 is about 25338.0680597397. The cubic root of 642017693 is about 862.6785484309.

The spelling of 642017693 in words is "six hundred forty-two million, seventeen thousand, six hundred ninety-three".