644352233 has 4 divisors (see below), whose sum is σ = 736402560. Its totient is φ = 552301908.

The previous prime is 644352223. The next prime is 644352251. The reversal of 644352233 is 332253446.

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 644352233 - 2⁸ = 644351977 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 644352233.

It is not an unprimeable number, because it can be changed into a prime (644352223) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46025153 + ... + 46025166.

It is an arithmetic number, because the mean of its divisors is an integer number (184100640).

Almost surely, 2^644352233 is an apocalyptic number.

It is an amenable number.

644352233 is a deficient number, since it is larger than the sum of its proper divisors (92050327).

644352233 is an equidigital number, since it uses as much as digits as its factorization.

644352233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 92050326.

The product of its digits is 51840, while the sum is 32.

The square root of 644352233 is about 25384.0940945309. The cubic root of 644352233 is about 863.7229232885.

The spelling of 644352233 in words is "six hundred forty-four million, three hundred fifty-two thousand, two hundred thirty-three".