645264361 has 4 divisors (see below), whose sum is σ = 737444992. Its totient is φ = 553083732.

The previous prime is 645264233. The next prime is 645264371. The reversal of 645264361 is 163462546.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 645264361 - 2⁷ = 645264233 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 645264361.

It is not an unprimeable number, because it can be changed into a prime (645264371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46090305 + ... + 46090318.

It is an arithmetic number, because the mean of its divisors is an integer number (184361248).

Almost surely, 2^645264361 is an apocalyptic number.

It is an amenable number.

645264361 is a deficient number, since it is larger than the sum of its proper divisors (92180631).

645264361 is an equidigital number, since it uses as much as digits as its factorization.

645264361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 92180630.

The product of its digits is 103680, while the sum is 37.

The square root of 645264361 is about 25402.0542673226. The cubic root of 645264361 is about 864.1302855833.

The spelling of 645264361 in words is "six hundred forty-five million, two hundred sixty-four thousand, three hundred sixty-one".