645738432 has 224 divisors, whose sum is σ = 1896099840. Its totient is φ = 193290240.

The previous prime is 645738419. The next prime is 645738433. The reversal of 645738432 is 234837546.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645738433) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7255444 + ... + 7255532.

Almost surely, 2^645738432 is an apocalyptic number.

645738432 is a gapful number since it is divisible by the number (62) 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 645738432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (948049920).

645738432 is an abundant number, since it is smaller than the sum of its proper divisors (1250361408).

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

645738432 is a wasteful number, since it uses less digits than its factorization.

645738432 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211 (or 201 counting only the distinct ones).

The product of its digits is 483840, while the sum is 42.

The square root of 645738432 is about 25411.3839056435. The cubic root of 645738432 is about 864.3418571756.

The spelling of 645738432 in words is "six hundred forty-five million, seven hundred thirty-eight thousand, four hundred thirty-two".