642005293 has 2 divisors, whose sum is σ = 642005294. Its totient is φ = 642005292.

The previous prime is 642005251. The next prime is 642005333. The reversal of 642005293 is 392500246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 512660164 + 129345129 = 22642^2 + 11373^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642005293 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642705293) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321002646 + 321002647.

It is an arithmetic number, because the mean of its divisors is an integer number (321002647).

Almost surely, 2^642005293 is an apocalyptic number.

It is an amenable number.

642005293 is a deficient number, since it is larger than the sum of its proper divisors (1).

642005293 is an equidigital number, since it uses as much as digits as its factorization.

642005293 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 642005293 is about 25337.8233674481. The cubic root of 642005293 is about 862.6729944392.

The spelling of 642005293 in words is "six hundred forty-two million, five thousand, two hundred ninety-three".