642910637 has 2 divisors, whose sum is σ = 642910638. Its totient is φ = 642910636.

The previous prime is 642910579. The next prime is 642910687. The reversal of 642910637 is 736019246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 615337636 + 27573001 = 24806^2 + 5251^2 .

It is a cyclic number.

It is not a de Polignac number, because 642910637 - 2¹⁸ = 642648493 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 642910637.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642910687) 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, 321455318 + 321455319.

It is an arithmetic number, because the mean of its divisors is an integer number (321455319).

Almost surely, 2^642910637 is an apocalyptic number.

It is an amenable number.

642910637 is a deficient number, since it is larger than the sum of its proper divisors (1).

642910637 is an equidigital number, since it uses as much as digits as its factorization.

642910637 is an odious number, because the sum of its binary digits is odd.

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

The square root of 642910637 is about 25355.6825386342. The cubic root of 642910637 is about 863.0783124797.

The spelling of 642910637 in words is "six hundred forty-two million, nine hundred ten thousand, six hundred thirty-seven".