21233863121 has 2 divisors, whose sum is σ = 21233863122. Its totient is φ = 21233863120.

The previous prime is 21233863033. The next prime is 21233863129. The reversal of 21233863121 is 12136833212.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21152502721 + 81360400 = 145439^2 + 9020^2 .

It is a cyclic number.

It is not a de Polignac number, because 21233863121 - 2¹⁴ = 21233846737 is a prime.

It is not a weakly prime, because it can be changed into another prime (21233863129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10616931560 + 10616931561.

It is an arithmetic number, because the mean of its divisors is an integer number (10616931561).

Almost surely, 2^21233863121 is an apocalyptic number.

It is an amenable number.

21233863121 is a deficient number, since it is larger than the sum of its proper divisors (1).

21233863121 is an equidigital number, since it uses as much as digits as its factorization.

21233863121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 32.

The spelling of 21233863121 in words is "twenty-one billion, two hundred thirty-three million, eight hundred sixty-three thousand, one hundred twenty-one".