644440083 has 16 divisors (see below), whose sum is σ = 982414080. Its totient is φ = 368097696.

The previous prime is 644440073. The next prime is 644440087. The reversal of 644440083 is 380044446.

It is not a de Polignac number, because 644440083 - 2¹⁴ = 644423699 is a prime.

It is not an unprimeable number, because it can be changed into a prime (644440087) 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, 62113 + ... + 71741.

It is an arithmetic number, because the mean of its divisors is an integer number (61400880).

Almost surely, 2^644440083 is an apocalyptic number.

644440083 is a deficient number, since it is larger than the sum of its proper divisors (337973997).

644440083 is a wasteful number, since it uses less digits than its factorization.

644440083 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12826.

The product of its (nonzero) digits is 36864, while the sum is 33.

The square root of 644440083 is about 25385.8244498775. The cubic root of 644440083 is about 863.7621743931.

The spelling of 644440083 in words is "six hundred forty-four million, four hundred forty thousand, eighty-three".