639473375 has 8 divisors (see below), whose sum is σ = 798062928. Its totient is φ = 511578600.

The previous prime is 639473371. The next prime is 639473381. The reversal of 639473375 is 573374936.

It is not a de Polignac number, because 639473375 - 2² = 639473371 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 (639473371) 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, 2557769 + ... + 2558018.

It is an arithmetic number, because the mean of its divisors is an integer number (99757866).

Almost surely, 2^639473375 is an apocalyptic number.

639473375 is a deficient number, since it is larger than the sum of its proper divisors (158589553).

639473375 is an equidigital number, since it uses as much as digits as its factorization.

639473375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5115802 (or 5115792 counting only the distinct ones).

The product of its digits is 1428840, while the sum is 47.

The square root of 639473375 is about 25287.8107988810. The cubic root of 639473375 is about 861.5374404903.

The spelling of 639473375 in words is "six hundred thirty-nine million, four hundred seventy-three thousand, three hundred seventy-five".