640919462400 has 720 divisors, whose sum is σ = 2627941128384. Its totient is φ = 146127421440.

The previous prime is 640919462389. The next prime is 640919462431. The reversal of 640919462400 is 4264919046.

640919462400 is a `hidden beast` number, since 6 + 4 + 0 + 9 + 19 + 4 + 624 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 441100074 + ... + 441101526.

Almost surely, 2^640919462400 is an apocalyptic number.

640919462400 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 640919462400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1313970564192).

640919462400 is an abundant number, since it is smaller than the sum of its proper divisors (1987021665984).

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

640919462400 is a wasteful number, since it uses less digits than its factorization.

640919462400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2041 (or 2017 counting only the distinct ones).

The product of its (nonzero) digits is 373248, while the sum is 45.

The spelling of 640919462400 in words is "six hundred forty billion, nine hundred nineteen million, four hundred sixty-two thousand, four hundred".