223456991 has 2 divisors, whose sum is σ = 223456992. Its totient is φ = 223456990.

The previous prime is 223456979. The next prime is 223456997. The reversal of 223456991 is 199654322.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 223456991 - 2¹⁸ = 223194847 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (223456997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 111728495 + 111728496.

It is an arithmetic number, because the mean of its divisors is an integer number (111728496).

Almost surely, 2^223456991 is an apocalyptic number.

223456991 is a deficient number, since it is larger than the sum of its proper divisors (1).

223456991 is an equidigital number, since it uses as much as digits as its factorization.

223456991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 116640, while the sum is 41.

The square root of 223456991 is about 14948.4778823799. The cubic root of 223456991 is about 606.8266546946.

The spelling of 223456991 in words is "two hundred twenty-three million, four hundred fifty-six thousand, nine hundred ninety-one".