4399990821 has 16 divisors (see below), whose sum is σ = 6525216000. Its totient is φ = 2930307264.

The previous prime is 4399990801. The next prime is 4399990823. The reversal of 4399990821 is 1280999934.

It is not a de Polignac number, because 4399990821 - 2⁶ = 4399990757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (4399990823) 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, 57021 + ... + 109778.

It is an arithmetic number, because the mean of its divisors is an integer number (407826000).

Almost surely, 2^4399990821 is an apocalyptic number.

It is an amenable number.

4399990821 is a deficient number, since it is larger than the sum of its proper divisors (2125225179).

4399990821 is a wasteful number, since it uses less digits than its factorization.

4399990821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167785 (or 167779 counting only the distinct ones).

The product of its (nonzero) digits is 1259712, while the sum is 54.

The square root of 4399990821 is about 66332.4266177561. The cubic root of 4399990821 is about 1638.6414017232.

The spelling of 4399990821 in words is "four billion, three hundred ninety-nine million, nine hundred ninety thousand, eight hundred twenty-one".