640854120 has 32 divisors (see below), whose sum is σ = 1922562720. Its totient is φ = 170894400.

The previous prime is 640854101. The next prime is 640854121. The reversal of 640854120 is 21458046.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (640854121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2670106 + ... + 2670345.

It is an arithmetic number, because the mean of its divisors is an integer number (60080085).

Almost surely, 2^640854120 is an apocalyptic number.

640854120 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

640854120 is an abundant number, since it is smaller than the sum of its proper divisors (1281708600).

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

640854120 is a wasteful number, since it uses less digits than its factorization.

640854120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5340465 (or 5340461 counting only the distinct ones).

The product of its (nonzero) digits is 7680, while the sum is 30.

The square root of 640854120 is about 25315.0966816246. The cubic root of 640854120 is about 862.1570692976.

The spelling of 640854120 in words is "six hundred forty million, eight hundred fifty-four thousand, one hundred twenty".