1231320243 has 16 divisors (see below), whose sum is σ = 1655860896. Its totient is φ = 813845760.

The previous prime is 1231320239. The next prime is 1231320263. The reversal of 1231320243 is 3420231321.

It is not a de Polignac number, because 1231320243 - 2² = 1231320239 is a prime.

It is a super-2 number, since 2×1231320243² = 3032299081643158098, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1231320263) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 447853 + ... + 450593.

It is an arithmetic number, because the mean of its divisors is an integer number (103491306).

Almost surely, 2^1231320243 is an apocalyptic number.

1231320243 is a deficient number, since it is larger than the sum of its proper divisors (424540653).

1231320243 is a wasteful number, since it uses less digits than its factorization.

1231320243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3974.

The product of its (nonzero) digits is 864, while the sum is 21.

The square root of 1231320243 is about 35090.1730260767. The cubic root of 1231320243 is about 1071.8244829759.

Adding to 1231320243 its reverse (3420231321), we get a palindrome (4651551564).

The spelling of 1231320243 in words is "one billion, two hundred thirty-one million, three hundred twenty thousand, two hundred forty-three".