642919509 has 24 divisors (see below), whose sum is σ = 959941632. Its totient is φ = 414214560.

The previous prime is 642919507. The next prime is 642919523. The reversal of 642919509 is 905919246.

It is not a de Polignac number, because 642919509 - 2¹ = 642919507 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642919507) 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 in 23 ways as a sum of consecutive naturals, for example, 310612 + ... + 312674.

It is an arithmetic number, because the mean of its divisors is an integer number (39997568).

Almost surely, 2^642919509 is an apocalyptic number.

It is an amenable number.

642919509 is a deficient number, since it is larger than the sum of its proper divisors (317022123).

642919509 is a wasteful number, since it uses less digits than its factorization.

642919509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3217 (or 3214 counting only the distinct ones).

The product of its (nonzero) digits is 174960, while the sum is 45.

The square root of 642919509 is about 25355.8574889511. The cubic root of 642919509 is about 863.0822825470.

The spelling of 642919509 in words is "six hundred forty-two million, nine hundred nineteen thousand, five hundred nine".