639364943 has 16 divisors (see below), whose sum is σ = 760119360. Its totient is φ = 526176000.

The previous prime is 639364931. The next prime is 639364949. The reversal of 639364943 is 349463936.

It is a happy number.

It is not a de Polignac number, because 639364943 - 2¹⁴ = 639348559 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639364949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28043 + ... + 45443.

It is an arithmetic number, because the mean of its divisors is an integer number (47507460).

Almost surely, 2^639364943 is an apocalyptic number.

639364943 is a deficient number, since it is larger than the sum of its proper divisors (120754417).

639364943 is a wasteful number, since it uses less digits than its factorization.

639364943 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17618.

The product of its digits is 1259712, while the sum is 47.

The square root of 639364943 is about 25285.6667501571. Note that the first 3 decimals coincide. The cubic root of 639364943 is about 861.4887423417.

The spelling of 639364943 in words is "six hundred thirty-nine million, three hundred sixty-four thousand, nine hundred forty-three".