638468851 has 8 divisors (see below), whose sum is σ = 654557904. Its totient is φ = 622404480.

The previous prime is 638468833. The next prime is 638468861. The reversal of 638468851 is 158864836.

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

It is a cyclic number.

It is not a de Polignac number, because 638468851 - 2⁵ = 638468819 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 638468795 and 638468804.

It is not an unprimeable number, because it can be changed into a prime (638468861) 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, 53320 + ... + 64186.

It is an arithmetic number, because the mean of its divisors is an integer number (81819738).

Almost surely, 2^638468851 is an apocalyptic number.

638468851 is a deficient number, since it is larger than the sum of its proper divisors (16089053).

638468851 is a wasteful number, since it uses less digits than its factorization.

638468851 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12341.

The product of its digits is 1105920, while the sum is 49.

The square root of 638468851 is about 25267.9411705821. The cubic root of 638468851 is about 861.0860854508.

The spelling of 638468851 in words is "six hundred thirty-eight million, four hundred sixty-eight thousand, eight hundred fifty-one".