4420091821 has 2 divisors, whose sum is σ = 4420091822. Its totient is φ = 4420091820.

The previous prime is 4420091801. The next prime is 4420091867. The reversal of 4420091821 is 1281900244.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4288416196 + 131675625 = 65486^2 + 11475^2 .

It is a cyclic number.

It is not a de Polignac number, because 4420091821 - 2⁵ = 4420091789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (4420091801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2210045910 + 2210045911.

It is an arithmetic number, because the mean of its divisors is an integer number (2210045911).

Almost surely, 2^4420091821 is an apocalyptic number.

It is an amenable number.

4420091821 is a deficient number, since it is larger than the sum of its proper divisors (1).

4420091821 is an equidigital number, since it uses as much as digits as its factorization.

4420091821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4608, while the sum is 31.

The square root of 4420091821 is about 66483.7711099483. The cubic root of 4420091821 is about 1641.1329447269.

The spelling of 4420091821 in words is "four billion, four hundred twenty million, ninety-one thousand, eight hundred twenty-one".