21805426233 has 20 divisors (see below), whose sum is σ = 33266597760. Its totient is φ = 14227651512.

The previous prime is 21805426217. The next prime is 21805426249. The reversal of 21805426233 is 33262450812.

21805426233 is a `hidden beast` number, since 2 + 1 + 80 + 542 + 6 + 2 + 33 = 666.

It is an interprime number because it is at equal distance from previous prime (21805426217) and next prime (21805426249).

It is not a de Polignac number, because 21805426233 - 2⁴ = 21805426217 is a prime.

It is a super-2 number, since 2×21805426233² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21805626233) 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 in 19 ways as a sum of consecutive naturals, for example, 2860053 + ... + 2867666.

It is an arithmetic number, because the mean of its divisors is an integer number (1663329888).

Almost surely, 2^21805426233 is an apocalyptic number.

It is an amenable number.

21805426233 is a deficient number, since it is larger than the sum of its proper divisors (11461171527).

21805426233 is an equidigital number, since it uses as much as digits as its factorization.

21805426233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5727778 (or 5727769 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The spelling of 21805426233 in words is "twenty-one billion, eight hundred five million, four hundred twenty-six thousand, two hundred thirty-three".