638620539 has 8 divisors (see below), whose sum is σ = 851922240. Its totient is φ = 425532936.

The previous prime is 638620531. The next prime is 638620559. The reversal of 638620539 is 935026836.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 638620539 - 2³ = 638620531 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 638620539.

It is not an unprimeable number, because it can be changed into a prime (638620531) 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, 46429 + ... + 58590.

It is an arithmetic number, because the mean of its divisors is an integer number (106490280).

Almost surely, 2^638620539 is an apocalyptic number.

638620539 is a deficient number, since it is larger than the sum of its proper divisors (213301701).

638620539 is a wasteful number, since it uses less digits than its factorization.

638620539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107049.

The product of its (nonzero) digits is 233280, while the sum is 42.

The square root of 638620539 is about 25270.9425823415. The cubic root of 638620539 is about 861.1542725850.

The spelling of 638620539 in words is "six hundred thirty-eight million, six hundred twenty thousand, five hundred thirty-nine".