639335789 has 4 divisors (see below), whose sum is σ = 641418624. Its totient is φ = 637252956.

The previous prime is 639335777. The next prime is 639335791. The reversal of 639335789 is 987533936.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 639335789 - 2¹⁶ = 639270253 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 639335789.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639335989) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1040957 + ... + 1041570.

It is an arithmetic number, because the mean of its divisors is an integer number (160354656).

Almost surely, 2^639335789 is an apocalyptic number.

It is an amenable number.

639335789 is a deficient number, since it is larger than the sum of its proper divisors (2082835).

639335789 is a wasteful number, since it uses less digits than its factorization.

639335789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2082834.

The product of its digits is 3674160, while the sum is 53.

The square root of 639335789 is about 25285.0902509760. The cubic root of 639335789 is about 861.4756479815.

The spelling of 639335789 in words is "six hundred thirty-nine million, three hundred thirty-five thousand, seven hundred eighty-nine".