640521024 has 224 divisors, whose sum is σ = 2043135360. Its totient is φ = 174489600.

The previous prime is 640521017. The next prime is 640521031. The reversal of 640521024 is 420125046.

It is an interprime number because it is at equal distance from previous prime (640521017) and next prime (640521031).

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

It is a junction number, because it is equal to n+sod(n) for n = 640520985 and 640521003.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1125412 + ... + 1125980.

It is an arithmetic number, because the mean of its divisors is an integer number (9121140).

Almost surely, 2^640521024 is an apocalyptic number.

640521024 is a gapful number since it is divisible by the number (64) 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 640521024, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1021567680).

640521024 is an abundant number, since it is smaller than the sum of its proper divisors (1402614336).

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

640521024 is a wasteful number, since it uses less digits than its factorization.

640521024 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 649 (or 639 counting only the distinct ones).

The product of its (nonzero) digits is 1920, while the sum is 24.

The square root of 640521024 is about 25308.5168273449. The cubic root of 640521024 is about 862.0076692847.

The spelling of 640521024 in words is "six hundred forty million, five hundred twenty-one thousand, twenty-four".