642558457 has 2 divisors, whose sum is σ = 642558458. Its totient is φ = 642558456.

The previous prime is 642558451. The next prime is 642558467. The reversal of 642558457 is 754855246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 340181136 + 302377321 = 18444^2 + 17389^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642558457 is a prime.

It is not a weakly prime, because it can be changed into another prime (642558451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321279228 + 321279229.

It is an arithmetic number, because the mean of its divisors is an integer number (321279229).

Almost surely, 2^642558457 is an apocalyptic number.

It is an amenable number.

642558457 is a deficient number, since it is larger than the sum of its proper divisors (1).

642558457 is an equidigital number, since it uses as much as digits as its factorization.

642558457 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1344000, while the sum is 46.

The square root of 642558457 is about 25348.7367929844. The cubic root of 642558457 is about 862.9206884796.

The spelling of 642558457 in words is "six hundred forty-two million, five hundred fifty-eight thousand, four hundred fifty-seven".