639213693 has 8 divisors (see below), whose sum is σ = 866257056. Its totient is φ = 419156400.

The previous prime is 639213691. The next prime is 639213763. The reversal of 639213693 is 396312936.

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

It is not a de Polignac number, because 639213693 - 2¹ = 639213691 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639213691) 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, 1746303 + ... + 1746668.

It is an arithmetic number, because the mean of its divisors is an integer number (108282132).

Almost surely, 2^639213693 is an apocalyptic number.

It is an amenable number.

639213693 is a deficient number, since it is larger than the sum of its proper divisors (227043363).

639213693 is a wasteful number, since it uses less digits than its factorization.

639213693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3493035.

The product of its digits is 157464, while the sum is 42.

The square root of 639213693 is about 25282.6757484250. The cubic root of 639213693 is about 861.4208049038.

The spelling of 639213693 in words is "six hundred thirty-nine million, two hundred thirteen thousand, six hundred ninety-three".