644167474 has 4 divisors (see below), whose sum is σ = 966251214. Its totient is φ = 322083736.

The previous prime is 644167471. The next prime is 644167481. The reversal of 644167474 is 474761446.

644167474 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 627151849 + 17015625 = 25043^2 + 4125^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 644167474.

It is not an unprimeable number, because it can be changed into a prime (644167471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 161041867 + ... + 161041870.

Almost surely, 2^644167474 is an apocalyptic number.

644167474 is a deficient number, since it is larger than the sum of its proper divisors (322083740).

644167474 is a wasteful number, since it uses less digits than its factorization.

644167474 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 322083739.

The product of its digits is 451584, while the sum is 43.

The square root of 644167474 is about 25380.4545664572. The cubic root of 644167474 is about 863.6403619034.

The spelling of 644167474 in words is "six hundred forty-four million, one hundred sixty-seven thousand, four hundred seventy-four".