642602655 has 24 divisors (see below), whose sum is σ = 1115449920. Its totient is φ = 342227520.

The previous prime is 642602617. The next prime is 642602657. The reversal of 642602655 is 556206246.

642602655 is a `hidden beast` number, since 6 + 42 + 602 + 6 + 5 + 5 = 666.

It is not a de Polignac number, because 642602655 - 2¹⁵ = 642569887 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642602657) 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 in 23 ways as a sum of consecutive naturals, for example, 22425 + ... + 42285.

It is an arithmetic number, because the mean of its divisors is an integer number (46477080).

Almost surely, 2^642602655 is an apocalyptic number.

642602655 is a deficient number, since it is larger than the sum of its proper divisors (472847265).

642602655 is a wasteful number, since it uses less digits than its factorization.

642602655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20591 (or 20588 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The square root of 642602655 is about 25349.6085768597. The cubic root of 642602655 is about 862.9404731875.

The spelling of 642602655 in words is "six hundred forty-two million, six hundred two thousand, six hundred fifty-five".