638840233 has 4 divisors (see below), whose sum is σ = 643717008. Its totient is φ = 633963460.

The previous prime is 638840231. The next prime is 638840239. The reversal of 638840233 is 332048836.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 638840233 - 2¹ = 638840231 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 638840192 and 638840201.

It is not an unprimeable number, because it can be changed into a prime (638840231) 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, 2438191 + ... + 2438452.

It is an arithmetic number, because the mean of its divisors is an integer number (160929252).

Almost surely, 2^638840233 is an apocalyptic number.

It is an amenable number.

638840233 is a deficient number, since it is larger than the sum of its proper divisors (4876775).

638840233 is a wasteful number, since it uses less digits than its factorization.

638840233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4876774.

The product of its (nonzero) digits is 82944, while the sum is 37.

The square root of 638840233 is about 25275.2889795547. The cubic root of 638840233 is about 861.2530107895.

The spelling of 638840233 in words is "six hundred thirty-eight million, eight hundred forty thousand, two hundred thirty-three".