645533376 has 112 divisors (see below), whose sum is σ = 1775581920. Its totient is φ = 206807040.

The previous prime is 645533347. The next prime is 645533377. The reversal of 645533376 is 673335546.

It is not an unprimeable number, because it can be changed into a prime (645533377) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 631746 + ... + 632766.

It is an arithmetic number, because the mean of its divisors is an integer number (15853410).

Almost surely, 2^645533376 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645533376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (887790960).

645533376 is an abundant number, since it is smaller than the sum of its proper divisors (1130048544).

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

645533376 is a wasteful number, since it uses less digits than its factorization.

645533376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1162 (or 1152 counting only the distinct ones).

The product of its digits is 680400, while the sum is 42.

The square root of 645533376 is about 25407.3488581552. The cubic root of 645533376 is about 864.2503561182.

The spelling of 645533376 in words is "six hundred forty-five million, five hundred thirty-three thousand, three hundred seventy-six".