638249580 has 36 divisors (see below), whose sum is σ = 1936024272. Its totient is φ = 170199840.

The previous prime is 638249569. The next prime is 638249627. The reversal of 638249580 is 85942836.

638249580 is a `hidden beast` number, since 6 + 3 + 82 + 495 + 80 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1772736 + ... + 1773095.

It is an arithmetic number, because the mean of its divisors is an integer number (53778452).

Almost surely, 2^638249580 is an apocalyptic number.

638249580 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

638249580 is an abundant number, since it is smaller than the sum of its proper divisors (1297774692).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

638249580 is a wasteful number, since it uses less digits than its factorization.

638249580 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3545846 (or 3545841 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 45.

The square root of 638249580 is about 25263.6018809670. The cubic root of 638249580 is about 860.9874991609.

The spelling of 638249580 in words is "six hundred thirty-eight million, two hundred forty-nine thousand, five hundred eighty".