223456781 has 2 divisors, whose sum is σ = 223456782. Its totient is φ = 223456780.

The previous prime is 223456769. The next prime is 223456811. The reversal of 223456781 is 187654322.

It is a happy number.

223456781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 190578025 + 32878756 = 13805^2 + 5734^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-223456781 is a prime.

It is a super-2 number, since 2×223456781² = 99865865949763922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (223426781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 111728390 + 111728391.

It is an arithmetic number, because the mean of its divisors is an integer number (111728391).

Almost surely, 2^223456781 is an apocalyptic number.

It is an amenable number.

223456781 is a deficient number, since it is larger than the sum of its proper divisors (1).

223456781 is an equidigital number, since it uses as much as digits as its factorization.

223456781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 80640, while the sum is 38.

The square root of 223456781 is about 14948.4708582517. The cubic root of 223456781 is about 606.8264646004.

The spelling of 223456781 in words is "two hundred twenty-three million, four hundred fifty-six thousand, seven hundred eighty-one".