639498240 has 288 divisors, whose sum is σ = 2307417840. Its totient is φ = 169869312.

The previous prime is 639498239. The next prime is 639498253. The reversal of 639498240 is 42894936.

639498240 is a `hidden beast` number, since 639 + 4 + 9 + 8 + 2 + 4 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2488192 + ... + 2488448.

Almost surely, 2^639498240 is an apocalyptic number.

639498240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639498240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1153708920).

639498240 is an abundant number, since it is smaller than the sum of its proper divisors (1667919600).

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

639498240 is an equidigital number, since it uses as much as digits as its factorization.

639498240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 299 (or 267 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The square root of 639498240 is about 25288.3024341295. The cubic root of 639498240 is about 861.5486068926.

The spelling of 639498240 in words is "six hundred thirty-nine million, four hundred ninety-eight thousand, two hundred forty".