999022020021 has 24 divisors (see below), whose sum is σ = 1454022497304. Its totient is φ = 660945116160.

The previous prime is 999022020011. The next prime is 999022020071. The reversal of 999022020021 is 120020220999.

999022020021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 176891742225 + 822130277796 = 420585^2 + 906714^2 .

It is not a de Polignac number, because 999022020021 - 2²² = 999017825717 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (999022020001) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3840631 + ... + 4092491.

It is an arithmetic number, because the mean of its divisors is an integer number (60584270721).

Almost surely, 2^999022020021 is an apocalyptic number.

It is an amenable number.

999022020021 is a deficient number, since it is larger than the sum of its proper divisors (455000477283).

999022020021 is a wasteful number, since it uses less digits than its factorization.

999022020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 255221 (or 255218 counting only the distinct ones).

The product of its (nonzero) digits is 11664, while the sum is 36.

The spelling of 999022020021 in words is "nine hundred ninety-nine billion, twenty-two million, twenty thousand, twenty-one".