642705293 has 2 divisors, whose sum is σ = 642705294. Its totient is φ = 642705292.

The previous prime is 642705289. The next prime is 642705313. The reversal of 642705293 is 392507246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 343657444 + 299047849 = 18538^2 + 17293^2 .

It is a cyclic number.

It is not a de Polignac number, because 642705293 - 2² = 642705289 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642705233) 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, 321352646 + 321352647.

It is an arithmetic number, because the mean of its divisors is an integer number (321352647).

Almost surely, 2^642705293 is an apocalyptic number.

It is an amenable number.

642705293 is a deficient number, since it is larger than the sum of its proper divisors (1).

642705293 is an equidigital number, since it uses as much as digits as its factorization.

642705293 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 38.

The square root of 642705293 is about 25351.6329454337. The cubic root of 642705293 is about 862.9864143657.

The spelling of 642705293 in words is "six hundred forty-two million, seven hundred five thousand, two hundred ninety-three".