4221020891 has 2 divisors, whose sum is σ = 4221020892. Its totient is φ = 4221020890.

The previous prime is 4221020879. The next prime is 4221020983. The reversal of 4221020891 is 1980201224.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 4221020891 - 2²² = 4216826587 is a prime.

It is not a weakly prime, because it can be changed into another prime (4221020591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2110510445 + 2110510446.

It is an arithmetic number, because the mean of its divisors is an integer number (2110510446).

Almost surely, 2^4221020891 is an apocalyptic number.

4221020891 is a deficient number, since it is larger than the sum of its proper divisors (1).

4221020891 is an equidigital number, since it uses as much as digits as its factorization.

4221020891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 4221020891 is about 64969.3842590493. The cubic root of 4221020891 is about 1616.1158906356.

The spelling of 4221020891 in words is "four billion, two hundred twenty-one million, twenty thousand, eight hundred ninety-one".