1223117591 has 4 divisors (see below), whose sum is σ = 1223221392. Its totient is φ = 1223013792.

The previous prime is 1223117551. The next prime is 1223117593. The reversal of 1223117591 is 1957113221.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 1223117591 - 2²² = 1218923287 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1223117593) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31571 + ... + 58676.

It is an arithmetic number, because the mean of its divisors is an integer number (305805348).

Almost surely, 2^1223117591 is an apocalyptic number.

1223117591 is a deficient number, since it is larger than the sum of its proper divisors (103801).

1223117591 is an equidigital number, since it uses as much as digits as its factorization.

1223117591 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103800.

The product of its digits is 3780, while the sum is 32.

The square root of 1223117591 is about 34973.0981041143. The cubic root of 1223117591 is about 1069.4391304603.

The spelling of 1223117591 in words is "one billion, two hundred twenty-three million, one hundred seventeen thousand, five hundred ninety-one".