638724045 has 32 divisors (see below), whose sum is σ = 1078387200. Its totient is φ = 321931584.

The previous prime is 638724013. The next prime is 638724067. The reversal of 638724045 is 540427836.

It is a happy number.

It is not a de Polignac number, because 638724045 - 2⁵ = 638724013 is a prime.

It is a super-2 number, since 2×638724045² = 815936811322324050, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 638723994 and 638724012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 123726 + ... + 128784.

It is an arithmetic number, because the mean of its divisors is an integer number (33699600).

Almost surely, 2^638724045 is an apocalyptic number.

It is an amenable number.

638724045 is a deficient number, since it is larger than the sum of its proper divisors (439663155).

638724045 is a wasteful number, since it uses less digits than its factorization.

638724045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5529.

The product of its (nonzero) digits is 161280, while the sum is 39.

The square root of 638724045 is about 25272.9904245619. The cubic root of 638724045 is about 861.2007946397.

The spelling of 638724045 in words is "six hundred thirty-eight million, seven hundred twenty-four thousand, forty-five".