638309133 has 96 divisors (see below), whose sum is σ = 1252869120. Its totient is φ = 317005920.

The previous prime is 638309117. The next prime is 638309233. The reversal of 638309133 is 331903836.

638309133 is a `hidden beast` number, since 638 + 3 + 0 + 9 + 13 + 3 = 666.

It is not a de Polignac number, because 638309133 - 2⁴ = 638309117 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (638309233) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 333766 + ... + 335672.

It is an arithmetic number, because the mean of its divisors is an integer number (13050720).

Almost surely, 2^638309133 is an apocalyptic number.

638309133 is a gapful number since it is divisible by the number (63) formed by its first and last digit.

It is an amenable number.

638309133 is a deficient number, since it is larger than the sum of its proper divisors (614559987).

638309133 is a wasteful number, since it uses less digits than its factorization.

638309133 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1964 (or 1951 counting only the distinct ones).

The product of its (nonzero) digits is 34992, while the sum is 36.

The square root of 638309133 is about 25264.7804858859. The cubic root of 638309133 is about 861.0142769792.

The spelling of 638309133 in words is "six hundred thirty-eight million, three hundred nine thousand, one hundred thirty-three".