642055651 has 2 divisors, whose sum is σ = 642055652. Its totient is φ = 642055650.

The previous prime is 642055607. The next prime is 642055669. The reversal of 642055651 is 156550246.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 642055651 - 2¹⁵ = 642022883 is a prime.

It is not a weakly prime, because it can be changed into another prime (642055681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321027825 + 321027826.

It is an arithmetic number, because the mean of its divisors is an integer number (321027826).

Almost surely, 2^642055651 is an apocalyptic number.

642055651 is a deficient number, since it is larger than the sum of its proper divisors (1).

642055651 is an equidigital number, since it uses as much as digits as its factorization.

642055651 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36000, while the sum is 34.

The square root of 642055651 is about 25338.8170797297. The cubic root of 642055651 is about 862.6955494717.

The spelling of 642055651 in words is "six hundred forty-two million, fifty-five thousand, six hundred fifty-one".