644230451 has 2 divisors, whose sum is σ = 644230452. Its totient is φ = 644230450.

The previous prime is 644230441. The next prime is 644230459. The reversal of 644230451 is 154032446.

644230451 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 644230451 - 2⁶ = 644230387 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (644230459) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322115225 + 322115226.

It is an arithmetic number, because the mean of its divisors is an integer number (322115226).

Almost surely, 2^644230451 is an apocalyptic number.

644230451 is a deficient number, since it is larger than the sum of its proper divisors (1).

644230451 is an equidigital number, since it uses as much as digits as its factorization.

644230451 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11520, while the sum is 29.

The square root of 644230451 is about 25381.6951955538. The cubic root of 644230451 is about 863.6685055715.

Adding to 644230451 its reverse (154032446), we get a palindrome (798262897).

The spelling of 644230451 in words is "six hundred forty-four million, two hundred thirty thousand, four hundred fifty-one".