21780522223 has 2 divisors, whose sum is σ = 21780522224. Its totient is φ = 21780522222.

The previous prime is 21780522191. The next prime is 21780522259. The reversal of 21780522223 is 32222508712.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21780522223 - 2⁵ = 21780522191 is a prime.

It is a super-2 number, since 2×21780522223² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21780522523) 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, 10890261111 + 10890261112.

It is an arithmetic number, because the mean of its divisors is an integer number (10890261112).

Almost surely, 2^21780522223 is an apocalyptic number.

21780522223 is a deficient number, since it is larger than the sum of its proper divisors (1).

21780522223 is an equidigital number, since it uses as much as digits as its factorization.

21780522223 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26880, while the sum is 34.

The spelling of 21780522223 in words is "twenty-one billion, seven hundred eighty million, five hundred twenty-two thousand, two hundred twenty-three".