638337249 has 24 divisors (see below), whose sum is σ = 1012549824. Its totient is φ = 384300000.

The previous prime is 638337229. The next prime is 638337251. The reversal of 638337249 is 942733836.

638337249 is a `hidden beast` number, since 638 + 3 + 3 + 7 + 2 + 4 + 9 = 666.

It is not a de Polignac number, because 638337249 - 2⁷ = 638337121 is a prime.

It is not an unprimeable number, because it can be changed into a prime (638337229) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 6402 + ... + 36299.

It is an arithmetic number, because the mean of its divisors is an integer number (42189576).

Almost surely, 2^638337249 is an apocalyptic number.

It is an amenable number.

638337249 is a deficient number, since it is larger than the sum of its proper divisors (374212575).

638337249 is a wasteful number, since it uses less digits than its factorization.

638337249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42869 (or 42866 counting only the distinct ones).

The product of its digits is 653184, while the sum is 45.

The square root of 638337249 is about 25265.3369065208. The cubic root of 638337249 is about 861.0269186710.

The spelling of 638337249 in words is "six hundred thirty-eight million, three hundred thirty-seven thousand, two hundred forty-nine".