638928434 has 8 divisors (see below), whose sum is σ = 978784128. Its totient is φ = 312667060.

The previous prime is 638928413. The next prime is 638928487. The reversal of 638928434 is 434829836.

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

It is a Harshad number since it is a multiple of its sum of digits (47).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3398462 + ... + 3398649.

It is an arithmetic number, because the mean of its divisors is an integer number (122348016).

Almost surely, 2^638928434 is an apocalyptic number.

638928434 is a deficient number, since it is larger than the sum of its proper divisors (339855694).

638928434 is a wasteful number, since it uses less digits than its factorization.

638928434 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6797160.

The product of its digits is 995328, while the sum is 47.

The square root of 638928434 is about 25277.0337262900. The cubic root of 638928434 is about 861.2926450503.

The spelling of 638928434 in words is "six hundred thirty-eight million, nine hundred twenty-eight thousand, four hundred thirty-four".