640203720 has 64 divisors (see below), whose sum is σ = 2068355520. Its totient is φ = 157588224.

The previous prime is 640203719. The next prime is 640203743. The reversal of 640203720 is 27302046.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 203634 + ... + 206753.

It is an arithmetic number, because the mean of its divisors is an integer number (32318055).

Almost surely, 2^640203720 is an apocalyptic number.

640203720 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

640203720 is an abundant number, since it is smaller than the sum of its proper divisors (1428151800).

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

640203720 is a wasteful number, since it uses less digits than its factorization.

640203720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 410414 (or 410410 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 24.

The square root of 640203720 is about 25302.2473310179. The cubic root of 640203720 is about 861.8653041115.

Adding to 640203720 its reverse (27302046), we get a palindrome (667505766).

It can be divided in two parts, 64020 and 3720, that multiplied together give a triangular number (238154400 = T₂₁₈₂₄).

The spelling of 640203720 in words is "six hundred forty million, two hundred three thousand, seven hundred twenty".