639402093 has 80 divisors (see below), whose sum is σ = 1115275392. Its totient is φ = 361152000.

The previous prime is 639402091. The next prime is 639402163. The reversal of 639402093 is 390204936.

It is a happy number.

It is not a de Polignac number, because 639402093 - 2¹ = 639402091 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639402091) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 839833 + ... + 840593.

Almost surely, 2^639402093 is an apocalyptic number.

It is an amenable number.

639402093 is a deficient number, since it is larger than the sum of its proper divisors (475873299).

639402093 is a wasteful number, since it uses less digits than its factorization.

639402093 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 848 (or 839 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 36.

The square root of 639402093 is about 25286.4013453872. The cubic root of 639402093 is about 861.5054274849.

The spelling of 639402093 in words is "six hundred thirty-nine million, four hundred two thousand, ninety-three".