642668730839 has 4 divisors (see below), whose sum is σ = 642670665480. Its totient is φ = 642666796200.

The previous prime is 642668730833. The next prime is 642668730857. The reversal of 642668730839 is 938037866246.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 642668730839 - 2²⁴ = 642651953623 is a prime.

It is a super-2 number, since 2×642668730839² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642668730833) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 328337 + ... + 1180314.

It is an arithmetic number, because the mean of its divisors is an integer number (160667666370).

Almost surely, 2^642668730839 is an apocalyptic number.

642668730839 is a deficient number, since it is larger than the sum of its proper divisors (1934641).

642668730839 is a wasteful number, since it uses less digits than its factorization.

642668730839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1934640.

The product of its (nonzero) digits is 62705664, while the sum is 62.

The spelling of 642668730839 in words is "six hundred forty-two billion, six hundred sixty-eight million, seven hundred thirty thousand, eight hundred thirty-nine".