640662120 has 384 divisors, whose sum is σ = 2515968000. Its totient is φ = 138309120.

The previous prime is 640662103. The next prime is 640662131. The reversal of 640662120 is 21266046.

It is a happy number.

640662120 is a `hidden beast` number, since 640 + 6 + 6 + 2 + 12 + 0 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 4609011 + ... + 4609149.

It is an arithmetic number, because the mean of its divisors is an integer number (6552000).

Almost surely, 2^640662120 is an apocalyptic number.

640662120 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 640662120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1257984000).

640662120 is an abundant number, since it is smaller than the sum of its proper divisors (1875305880).

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

640662120 is a wasteful number, since it uses less digits than its factorization.

640662120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 253 (or 246 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 640662120 is about 25311.3041939763. The cubic root of 640662120 is about 862.0709598975.

The spelling of 640662120 in words is "six hundred forty million, six hundred sixty-two thousand, one hundred twenty".