645354 has 64 divisors (see below), whose sum is σ = 1641600. Its totient is φ = 186624.

The previous prime is 645353. The next prime is 645367. The reversal of 645354 is 453546.

645354 = T₂₆₇ + T₂₆₈ + ... + T₂₈₃.

645354 = 52² + 53² + ... + 127².

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 645354.

It is not an unprimeable number, because it can be changed into a prime (645353) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 17424 + ... + 17460.

It is an arithmetic number, because the mean of its divisors is an integer number (25650).

2⁶⁴⁵³⁵⁴ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 645354, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (820800).

645354 is an abundant number, since it is smaller than the sum of its proper divisors (996246).

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

645354 is a wasteful number, since it uses less digits than its factorization.

645354 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84 (or 78 counting only the distinct ones).

The product of its digits is 7200, while the sum is 27.

The square root of 645354 is about 803.3392807525. The cubic root of 645354 is about 86.4170298221.

It can be divided in two parts, 645 and 354, that added together give a palindrome (999).

The spelling of 645354 in words is "six hundred forty-five thousand, three hundred fifty-four".