639894573 has 12 divisors (see below), whose sum is σ = 958525568. Its totient is φ = 426596220.

The previous prime is 639894571. The next prime is 639894587. The reversal of 639894573 is 375498936.

639894573 is a `hidden beast` number, since 63 + 9 + 8 + 9 + 4 + 573 = 666.

It is not a de Polignac number, because 639894573 - 2¹ = 639894571 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639894571) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1316413 + ... + 1316898.

Almost surely, 2^639894573 is an apocalyptic number.

It is an amenable number.

639894573 is a deficient number, since it is larger than the sum of its proper divisors (318630995).

639894573 is an equidigital number, since it uses as much as digits as its factorization.

639894573 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2633326 (or 2633314 counting only the distinct ones).

The product of its digits is 4898880, while the sum is 54.

The square root of 639894573 is about 25296.1375114858. The cubic root of 639894573 is about 861.7265535004.

The spelling of 639894573 in words is "six hundred thirty-nine million, eight hundred ninety-four thousand, five hundred seventy-three".