642685379 has 8 divisors (see below), whose sum is σ = 750125568. Its totient is φ = 539152200.

The previous prime is 642685363. The next prime is 642685387. The reversal of 642685379 is 973586246.

It is a happy number.

642685379 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 642685379 - 2⁴ = 642685363 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642685319) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 976397 + ... + 977054.

It is an arithmetic number, because the mean of its divisors is an integer number (93765696).

Almost surely, 2^642685379 is an apocalyptic number.

642685379 is a deficient number, since it is larger than the sum of its proper divisors (107440189).

642685379 is a wasteful number, since it uses less digits than its factorization.

642685379 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1953505.

The product of its digits is 2177280, while the sum is 50.

The square root of 642685379 is about 25351.2401866260. The cubic root of 642685379 is about 862.9775011623.

The spelling of 642685379 in words is "six hundred forty-two million, six hundred eighty-five thousand, three hundred seventy-nine".