645894950400 has 1440 divisors, whose sum is σ = 2825125966080. Its totient is φ = 144037232640.

The previous prime is 645894950369. The next prime is 645894950429. The reversal of 645894950400 is 4059498546.

645894950400 is a `hidden beast` number, since 6 + 4 + 589 + 4 + 9 + 50 + 4 + 0 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1440).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 728178757 + ... + 728179643.

It is an arithmetic number, because the mean of its divisors is an integer number (1961893032).

Almost surely, 2^645894950400 is an apocalyptic number.

645894950400 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 645894950400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1412562983040).

645894950400 is an abundant number, since it is smaller than the sum of its proper divisors (2179231015680).

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

645894950400 is a wasteful number, since it uses less digits than its factorization.

645894950400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 981 (or 947 counting only the distinct ones).

The product of its (nonzero) digits is 6220800, while the sum is 54.

The spelling of 645894950400 in words is "six hundred forty-five billion, eight hundred ninety-four million, nine hundred fifty thousand, four hundred".