642505267 has 2 divisors, whose sum is σ = 642505268. Its totient is φ = 642505266.

The previous prime is 642505261. The next prime is 642505307. The reversal of 642505267 is 762505246.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 642505267 - 2⁷ = 642505139 is a prime.

It is not a weakly prime, because it can be changed into another prime (642505261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321252633 + 321252634.

It is an arithmetic number, because the mean of its divisors is an integer number (321252634).

Almost surely, 2^642505267 is an apocalyptic number.

642505267 is a deficient number, since it is larger than the sum of its proper divisors (1).

642505267 is an equidigital number, since it uses as much as digits as its factorization.

642505267 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 100800, while the sum is 37.

The square root of 642505267 is about 25347.6876065648. The cubic root of 642505267 is about 862.8968774072.

The spelling of 642505267 in words is "six hundred forty-two million, five hundred five thousand, two hundred sixty-seven".