642868231 has 2 divisors, whose sum is σ = 642868232. Its totient is φ = 642868230.

The previous prime is 642868207. The next prime is 642868273. The reversal of 642868231 is 132868246.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 642868231 - 2¹⁷ = 642737159 is a prime.

It is a super-2 number, since 2×642868231² = 826559124858138722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642868631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321434115 + 321434116.

It is an arithmetic number, because the mean of its divisors is an integer number (321434116).

Almost surely, 2^642868231 is an apocalyptic number.

642868231 is a deficient number, since it is larger than the sum of its proper divisors (1).

642868231 is an equidigital number, since it uses as much as digits as its factorization.

642868231 is an evil number, because the sum of its binary digits is even.

The product of its digits is 110592, while the sum is 40.

The square root of 642868231 is about 25354.8463020386. The cubic root of 642868231 is about 863.0593360199.

The spelling of 642868231 in words is "six hundred forty-two million, eight hundred sixty-eight thousand, two hundred thirty-one".