644054447 has 2 divisors, whose sum is σ = 644054448. Its totient is φ = 644054446.

The previous prime is 644054431. The next prime is 644054459. The reversal of 644054447 is 744450446.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644054447 - 2⁴ = 644054431 is a prime.

It is a super-2 number, since 2×644054447² = 829612261400951618, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 644054447.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (644054407) 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 as a sum of consecutive naturals, namely, 322027223 + 322027224.

It is an arithmetic number, because the mean of its divisors is an integer number (322027224).

Almost surely, 2^644054447 is an apocalyptic number.

644054447 is a deficient number, since it is larger than the sum of its proper divisors (1).

644054447 is an equidigital number, since it uses as much as digits as its factorization.

644054447 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 215040, while the sum is 38.

The square root of 644054447 is about 25378.2278144082. The cubic root of 644054447 is about 863.5898468884.

The spelling of 644054447 in words is "six hundred forty-four million, fifty-four thousand, four hundred forty-seven".