639700343 has 2 divisors, whose sum is σ = 639700344. Its totient is φ = 639700342.

The previous prime is 639700333. The next prime is 639700381. The reversal of 639700343 is 343007936.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-639700343 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (639700333) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 319850171 + 319850172.

It is an arithmetic number, because the mean of its divisors is an integer number (319850172).

Almost surely, 2^639700343 is an apocalyptic number.

639700343 is a deficient number, since it is larger than the sum of its proper divisors (1).

639700343 is an equidigital number, since it uses as much as digits as its factorization.

639700343 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 40824, while the sum is 35.

The square root of 639700343 is about 25292.2980964562. The cubic root of 639700343 is about 861.6393568002.

The spelling of 639700343 in words is "six hundred thirty-nine million, seven hundred thousand, three hundred forty-three".