1223889991 has 8 divisors (see below), whose sum is σ = 1232812800. Its totient is φ = 1214993760.

The previous prime is 1223889971. The next prime is 1223890001. The reversal of 1223889991 is 1999883221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1223889991 - 2¹⁵ = 1223857223 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 (1223889971) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90925 + ... + 103513.

It is an arithmetic number, because the mean of its divisors is an integer number (154101600).

Almost surely, 2^1223889991 is an apocalyptic number.

1223889991 is a deficient number, since it is larger than the sum of its proper divisors (8922809).

1223889991 is a wasteful number, since it uses less digits than its factorization.

1223889991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13289.

The product of its digits is 559872, while the sum is 52.

The square root of 1223889991 is about 34984.1391347565. The cubic root of 1223889991 is about 1069.6642003883.

The spelling of 1223889991 in words is "one billion, two hundred twenty-three million, eight hundred eighty-nine thousand, nine hundred ninety-one".