223660991 has 2 divisors, whose sum is σ = 223660992. Its totient is φ = 223660990.

The previous prime is 223660981. The next prime is 223661033. The reversal of 223660991 is 199066322.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 223660991 - 2¹⁰ = 223659967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (223660961) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 111830495 + 111830496.

It is an arithmetic number, because the mean of its divisors is an integer number (111830496).

Almost surely, 2^223660991 is an apocalyptic number.

223660991 is a deficient number, since it is larger than the sum of its proper divisors (1).

223660991 is an equidigital number, since it uses as much as digits as its factorization.

223660991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34992, while the sum is 38.

The square root of 223660991 is about 14955.2997629603. The cubic root of 223660991 is about 607.0112614130.

The spelling of 223660991 in words is "two hundred twenty-three million, six hundred sixty thousand, nine hundred ninety-one".