638670983 has 4 divisors (see below), whose sum is σ = 638781768. Its totient is φ = 638560200.

The previous prime is 638670979. The next prime is 638671013. The reversal of 638670983 is 389076836.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 638670983 - 2² = 638670979 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638670953) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46241 + ... + 58442.

It is an arithmetic number, because the mean of its divisors is an integer number (159695442).

Almost surely, 2^638670983 is an apocalyptic number.

638670983 is a deficient number, since it is larger than the sum of its proper divisors (110785).

638670983 is a wasteful number, since it uses less digits than its factorization.

638670983 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110784.

The product of its (nonzero) digits is 1306368, while the sum is 50.

The square root of 638670983 is about 25271.9406259195. The cubic root of 638670983 is about 861.1769458939.

The spelling of 638670983 in words is "six hundred thirty-eight million, six hundred seventy thousand, nine hundred eighty-three".