21033312021 has 24 divisors (see below), whose sum is σ = 31734683136. Its totient is φ = 13398881760.

The previous prime is 21033312011. The next prime is 21033312023. The reversal of 21033312021 is 12021333012.

21033312021 is a `hidden beast` number, since 210 + 333 + 120 + 2 + 1 = 666.

It is not a de Polignac number, because 21033312021 - 2²² = 21029117717 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21033311985 and 21033312003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033312023) 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, 153871 + ... + 256403.

It is an arithmetic number, because the mean of its divisors is an integer number (1322278464).

Almost surely, 2^21033312021 is an apocalyptic number.

It is an amenable number.

21033312021 is a deficient number, since it is larger than the sum of its proper divisors (10701371115).

21033312021 is a wasteful number, since it uses less digits than its factorization.

21033312021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103553 (or 103550 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21033312021 its reverse (12021333012), we get a palindrome (33054645033).

The spelling of 21033312021 in words is "twenty-one billion, thirty-three million, three hundred twelve thousand, twenty-one".