639297371 has 2 divisors, whose sum is σ = 639297372. Its totient is φ = 639297370.

The previous prime is 639297367. The next prime is 639297403. The reversal of 639297371 is 173792936.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 639297371 - 2² = 639297367 is a prime.

It is a super-2 number, since 2×639297371² = 817402257135023282, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (639297331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319648685 + 319648686.

It is an arithmetic number, because the mean of its divisors is an integer number (319648686).

Almost surely, 2^639297371 is an apocalyptic number.

639297371 is a deficient number, since it is larger than the sum of its proper divisors (1).

639297371 is an equidigital number, since it uses as much as digits as its factorization.

639297371 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 428652, while the sum is 47.

The square root of 639297371 is about 25284.3305428481. The cubic root of 639297371 is about 861.4583921383.

The spelling of 639297371 in words is "six hundred thirty-nine million, two hundred ninety-seven thousand, three hundred seventy-one".