133638687 has 64 divisors (see below), whose sum is σ = 246400000. Its totient is φ = 69704064.

The previous prime is 133638677. The next prime is 133638727. The reversal of 133638687 is 786836331.

133638687 is a `hidden beast` number, since 1 + 3 + 3 + 638 + 6 + 8 + 7 = 666.

It is not a de Polignac number, because 133638687 - 2¹⁴ = 133622303 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (133638607) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 267564 + ... + 268062.

It is an arithmetic number, because the mean of its divisors is an integer number (3850000).

Almost surely, 2^133638687 is an apocalyptic number.

133638687 is a deficient number, since it is larger than the sum of its proper divisors (112761313).

133638687 is a wasteful number, since it uses less digits than its factorization.

133638687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 637 (or 631 counting only the distinct ones).

The product of its digits is 435456, while the sum is 45.

The square root of 133638687 is about 11560.2200238577. The cubic root of 133638687 is about 511.2626499182.

The spelling of 133638687 in words is "one hundred thirty-three million, six hundred thirty-eight thousand, six hundred eighty-seven".