644226699 has 8 divisors (see below), whose sum is σ = 859138560. Its totient is φ = 429399656.

The previous prime is 644226689. The next prime is 644226719. The reversal of 644226699 is 996622446.

It is a happy number.

644226699 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 644226699 - 2⁴ = 644226683 is a prime.

It is not an unprimeable number, because it can be changed into a prime (644226629) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 627 + ... + 35900.

It is an arithmetic number, because the mean of its divisors is an integer number (107392320).

Almost surely, 2^644226699 is an apocalyptic number.

644226699 is a deficient number, since it is larger than the sum of its proper divisors (214911861).

644226699 is a wasteful number, since it uses less digits than its factorization.

644226699 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42409.

The product of its digits is 1119744, while the sum is 48.

The square root of 644226699 is about 25381.6212839133. The cubic root of 644226699 is about 863.6668288990. Note that the first 3 decimals are identical.

The spelling of 644226699 in words is "six hundred forty-four million, two hundred twenty-six thousand, six hundred ninety-nine".