1223516491 has 4 divisors (see below), whose sum is σ = 1228031584. Its totient is φ = 1219001400.

The previous prime is 1223516477. The next prime is 1223516507. The reversal of 1223516491 is 1946153221.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1946153221 = 67 ⋅29047063.

It is a cyclic number.

It is not a de Polignac number, because 1223516491 - 2²³ = 1215127883 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1223516461) 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, 2257140 + ... + 2257681.

It is an arithmetic number, because the mean of its divisors is an integer number (307007896).

Almost surely, 2^1223516491 is an apocalyptic number.

1223516491 is a deficient number, since it is larger than the sum of its proper divisors (4515093).

1223516491 is an equidigital number, since it uses as much as digits as its factorization.

1223516491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4515092.

The product of its digits is 12960, while the sum is 34.

The square root of 1223516491 is about 34978.8005940741. The cubic root of 1223516491 is about 1069.5553779098. Note that the first 3 decimals are identical.

The spelling of 1223516491 in words is "one billion, two hundred twenty-three million, five hundred sixteen thousand, four hundred ninety-one".