642915755 has 4 divisors (see below), whose sum is σ = 771498912. Its totient is φ = 514332600.

The previous prime is 642915733. The next prime is 642915857. The reversal of 642915755 is 557519246.

It is a happy number.

642915755 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 642915755 - 2¹⁰ = 642914731 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64291571 + ... + 64291580.

It is an arithmetic number, because the mean of its divisors is an integer number (192874728).

Almost surely, 2^642915755 is an apocalyptic number.

642915755 is a deficient number, since it is larger than the sum of its proper divisors (128583157).

642915755 is a wasteful number, since it uses less digits than its factorization.

642915755 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128583156.

The product of its digits is 378000, while the sum is 44.

The square root of 642915755 is about 25355.7834625554. The cubic root of 642915755 is about 863.0806027011.

The spelling of 642915755 in words is "six hundred forty-two million, nine hundred fifteen thousand, seven hundred fifty-five".