642457 has 2 divisors, whose sum is σ = 642458. Its totient is φ = 642456.

The previous prime is 642427. The next prime is 642487. The reversal of 642457 is 754246.

It is a balanced prime because it is at equal distance from previous prime (642427) and next prime (642487).

It can be written as a sum of positive squares in only one way, i.e., 341056 + 301401 = 584^2 + 549^2 .

It is a cyclic number.

It is not a de Polignac number, because 642457 - 2¹⁹ = 118169 is a prime.

It is not a weakly prime, because it can be changed into another prime (642407) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321228 + 321229.

It is an arithmetic number, because the mean of its divisors is an integer number (321229).

2⁶⁴²⁴⁵⁷ is an apocalyptic number.

It is an amenable number.

642457 is a deficient number, since it is larger than the sum of its proper divisors (1).

642457 is an equidigital number, since it uses as much as digits as its factorization.

642457 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6720, while the sum is 28.

The square root of 642457 is about 801.5341539822. The cubic root of 642457 is about 86.2875269031.

The spelling of 642457 in words is "six hundred forty-two thousand, four hundred fifty-seven".