640608552 has 96 divisors (see below), whose sum is σ = 1896410880. Its totient is φ = 194480640.

The previous prime is 640608547. The next prime is 640608557. The reversal of 640608552 is 255806046.

640608552 is a `hidden beast` number, since 6 + 40 + 60 + 8 + 552 = 666.

It is an interprime number because it is at equal distance from previous prime (640608547) and next prime (640608557).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (640608557) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29503 + ... + 46385.

It is an arithmetic number, because the mean of its divisors is an integer number (19754280).

Almost surely, 2^640608552 is an apocalyptic number.

640608552 is a gapful number since it is divisible by the number (62) 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 640608552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (948205440).

640608552 is an abundant number, since it is smaller than the sum of its proper divisors (1255802328).

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

640608552 is a wasteful number, since it uses less digits than its factorization.

640608552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16943 (or 16936 counting only the distinct ones).

The product of its (nonzero) digits is 57600, while the sum is 36.

The square root of 640608552 is about 25310.2459885320. The cubic root of 640608552 is about 862.0469323054.

The spelling of 640608552 in words is "six hundred forty million, six hundred eight thousand, five hundred fifty-two".