645403356 has 96 divisors (see below), whose sum is σ = 1819883520. Its totient is φ = 196613568.

The previous prime is 645403331. The next prime is 645403357. The reversal of 645403356 is 653304546.

645403356 is a `hidden beast` number, since 64 + 540 + 3 + 3 + 56 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 645403356.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (645403357) 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, 142381 + ... + 146843.

It is an arithmetic number, because the mean of its divisors is an integer number (18957120).

Almost surely, 2^645403356 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 645403356, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (909941760).

645403356 is an abundant number, since it is smaller than the sum of its proper divisors (1174480164).

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

645403356 is a wasteful number, since it uses less digits than its factorization.

645403356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4592 (or 4584 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 36.

The square root of 645403356 is about 25404.7900207815. The cubic root of 645403356 is about 864.1923279405.

It can be divided in two parts, 64540 and 3356, that added together give a triangular number (67896 = T₃₆₈).

The spelling of 645403356 in words is "six hundred forty-five million, four hundred three thousand, three hundred fifty-six".