4021422991721 has 2 divisors, whose sum is σ = 4021422991722. Its totient is φ = 4021422991720.

The previous prime is 4021422991717. The next prime is 4021422991741. The reversal of 4021422991721 is 1271992241204.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3966327166096 + 55095825625 = 1991564^2 + 234725^2 .

It is a cyclic number.

It is not a de Polignac number, because 4021422991721 - 2² = 4021422991717 is a prime.

It is not a weakly prime, because it can be changed into another prime (4021422991741) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2010711495860 + 2010711495861.

It is an arithmetic number, because the mean of its divisors is an integer number (2010711495861).

Almost surely, 2^{4021422991721} is an apocalyptic number.

It is an amenable number.

4021422991721 is a deficient number, since it is larger than the sum of its proper divisors (1).

4021422991721 is an equidigital number, since it uses as much as digits as its factorization.

4021422991721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 145152, while the sum is 44.

The spelling of 4021422991721 in words is "four trillion, twenty-one billion, four hundred twenty-two million, nine hundred ninety-one thousand, seven hundred twenty-one".