21123576433 has 2 divisors, whose sum is σ = 21123576434. Its totient is φ = 21123576432.

The previous prime is 21123576379. The next prime is 21123576437. The reversal of 21123576433 is 33467532112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 11908920384 + 9214656049 = 109128^2 + 95993^2 .

It is a cyclic number.

It is not a de Polignac number, because 21123576433 - 2²⁵ = 21090022001 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21123576392 and 21123576401.

It is not a weakly prime, because it can be changed into another prime (21123576437) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10561788216 + 10561788217.

It is an arithmetic number, because the mean of its divisors is an integer number (10561788217).

Almost surely, 2^21123576433 is an apocalyptic number.

It is an amenable number.

21123576433 is a deficient number, since it is larger than the sum of its proper divisors (1).

21123576433 is an equidigital number, since it uses as much as digits as its factorization.

21123576433 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 90720, while the sum is 37.

The spelling of 21123576433 in words is "twenty-one billion, one hundred twenty-three million, five hundred seventy-six thousand, four hundred thirty-three".