644826099 has 16 divisors (see below), whose sum is σ = 910891008. Its totient is φ = 404353152.

The previous prime is 644826079. The next prime is 644826103. The reversal of 644826099 is 990628446.

It is not a de Polignac number, because 644826099 - 2⁵ = 644826067 is a prime.

It is not an unprimeable number, because it can be changed into a prime (644826019) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 122214 + ... + 127380.

It is an arithmetic number, because the mean of its divisors is an integer number (56930688).

Almost surely, 2^644826099 is an apocalyptic number.

644826099 is a deficient number, since it is larger than the sum of its proper divisors (266064909).

644826099 is a wasteful number, since it uses less digits than its factorization.

644826099 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7634.

The product of its (nonzero) digits is 746496, while the sum is 48.

The square root of 644826099 is about 25393.4262950079. The cubic root of 644826099 is about 863.9346028712.

The spelling of 644826099 in words is "six hundred forty-four million, eight hundred twenty-six thousand, ninety-nine".