639031373 has 6 divisors (see below), whose sum is σ = 641392842. Its totient is φ = 636678560.

The previous prime is 639031369. The next prime is 639031397. The reversal of 639031373 is 373130936.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 169572484 + 469458889 = 13022^2 + 21667^2 .

It is not a de Polignac number, because 639031373 - 2² = 639031369 is a prime.

It is a super-2 number, since 2×639031373² = 816722191356530258, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639031363) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 74915 + ... + 83007.

It is an arithmetic number, because the mean of its divisors is an integer number (106898807).

Almost surely, 2^639031373 is an apocalyptic number.

It is an amenable number.

639031373 is a deficient number, since it is larger than the sum of its proper divisors (2361469).

639031373 is an frugal number, since it uses more digits than its factorization.

639031373 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8655 (or 8374 counting only the distinct ones).

The product of its (nonzero) digits is 30618, while the sum is 35.

The square root of 639031373 is about 25279.0698602619. The cubic root of 639031373 is about 861.3388974096.

The spelling of 639031373 in words is "six hundred thirty-nine million, thirty-one thousand, three hundred seventy-three".