638983923 has 8 divisors (see below), whose sum is σ = 852697488. Its totient is φ = 425629824.

The previous prime is 638983909. The next prime is 638983937. The reversal of 638983923 is 329389836.

It is an interprime number because it is at equal distance from previous prime (638983909) and next prime (638983937).

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

It is not a de Polignac number, because 638983923 - 2¹⁸ = 638721779 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638983993) 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, 85690 + ... + 92847.

It is an arithmetic number, because the mean of its divisors is an integer number (106587186).

Almost surely, 2^638983923 is an apocalyptic number.

638983923 is a deficient number, since it is larger than the sum of its proper divisors (213713565).

638983923 is a wasteful number, since it uses less digits than its factorization.

638983923 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179733.

The product of its digits is 1679616, while the sum is 51.

The square root of 638983923 is about 25278.1313193836. The cubic root of 638983923 is about 861.3175778813.

The spelling of 638983923 in words is "six hundred thirty-eight million, nine hundred eighty-three thousand, nine hundred twenty-three".