21153776233 has 2 divisors, whose sum is σ = 21153776234. Its totient is φ = 21153776232.

The previous prime is 21153776173. The next prime is 21153776239. The reversal of 21153776233 is 33267735112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17980932649 + 3172843584 = 134093^2 + 56328^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21153776233 is a prime.

It is not a weakly prime, because it can be changed into another prime (21153776239) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10576888116 + 10576888117.

It is an arithmetic number, because the mean of its divisors is an integer number (10576888117).

Almost surely, 2^21153776233 is an apocalyptic number.

It is an amenable number.

21153776233 is a deficient number, since it is larger than the sum of its proper divisors (1).

21153776233 is an equidigital number, since it uses as much as digits as its factorization.

21153776233 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 158760, while the sum is 40.

The spelling of 21153776233 in words is "twenty-one billion, one hundred fifty-three million, seven hundred seventy-six thousand, two hundred thirty-three".