21421134233 has 2 divisors, whose sum is σ = 21421134234. Its totient is φ = 21421134232.

The previous prime is 21421134209. The next prime is 21421134247. The reversal of 21421134233 is 33243112412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17724129424 + 3697004809 = 133132^2 + 60803^2 .

It is a cyclic number.

It is not a de Polignac number, because 21421134233 - 2¹⁸ = 21420872089 is a prime.

It is not a weakly prime, because it can be changed into another prime (21421134253) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10710567116 + 10710567117.

It is an arithmetic number, because the mean of its divisors is an integer number (10710567117).

Almost surely, 2^21421134233 is an apocalyptic number.

It is an amenable number.

21421134233 is a deficient number, since it is larger than the sum of its proper divisors (1).

21421134233 is an equidigital number, since it uses as much as digits as its factorization.

21421134233 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3456, while the sum is 26.

Adding to 21421134233 its reverse (33243112412), we get a palindrome (54664246645).

The spelling of 21421134233 in words is "twenty-one billion, four hundred twenty-one million, one hundred thirty-four thousand, two hundred thirty-three".