645431322510 has 192 divisors, whose sum is σ = 1848864745728. Its totient is φ = 155225014272.

The previous prime is 645431322509. The next prime is 645431322553. The reversal of 645431322510 is 15223134546.

645431322510 is a `hidden beast` number, since 6 + 4 + 5 + 4 + 3 + 132 + 2 + 510 = 666.

645431322510 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

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, 32599174 + ... + 32618966.

It is an arithmetic number, because the mean of its divisors is an integer number (9629503884).

Almost surely, 2^645431322510 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645431322510, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (924432372864).

645431322510 is an abundant number, since it is smaller than the sum of its proper divisors (1203433423218).

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

645431322510 is a wasteful number, since it uses less digits than its factorization.

645431322510 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20459 (or 20456 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The spelling of 645431322510 in words is "six hundred forty-five billion, four hundred thirty-one million, three hundred twenty-two thousand, five hundred ten".