642458777 has 2 divisors, whose sum is σ = 642458778. Its totient is φ = 642458776.

The previous prime is 642458759. The next prime is 642458797. The reversal of 642458777 is 777854246.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 584865856 + 57592921 = 24184^2 + 7589^2 .

It is a cyclic number.

It is not a de Polignac number, because 642458777 - 2²⁶ = 575349913 is a prime.

It is not a weakly prime, because it can be changed into another prime (642458797) 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, 321229388 + 321229389.

It is an arithmetic number, because the mean of its divisors is an integer number (321229389).

Almost surely, 2^642458777 is an apocalyptic number.

It is an amenable number.

642458777 is a deficient number, since it is larger than the sum of its proper divisors (1).

642458777 is an equidigital number, since it uses as much as digits as its factorization.

642458777 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2634240, while the sum is 50.

The square root of 642458777 is about 25346.7705437991. The cubic root of 642458777 is about 862.8760645851.

It can be divided in two parts, 64245 and 8777, that multiplied together give a palindrome (563878365).

The spelling of 642458777 in words is "six hundred forty-two million, four hundred fifty-eight thousand, seven hundred seventy-seven".