1251243223 has 4 divisors (see below), whose sum is σ = 1252532808. Its totient is φ = 1249953640.

The previous prime is 1251243209. The next prime is 1251243241. The reversal of 1251243223 is 3223421521.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1251243223 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 (1251243523) 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, 643336 + ... + 645277.

It is an arithmetic number, because the mean of its divisors is an integer number (313133202).

Almost surely, 2^1251243223 is an apocalyptic number.

1251243223 is a deficient number, since it is larger than the sum of its proper divisors (1289585).

1251243223 is an equidigital number, since it uses as much as digits as its factorization.

1251243223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1289584.

The product of its digits is 2880, while the sum is 25.

The square root of 1251243223 is about 35372.9165181499. The cubic root of 1251243223 is about 1077.5743523860.

Adding to 1251243223 its reverse (3223421521), we get a palindrome (4474664744).

The spelling of 1251243223 in words is "one billion, two hundred fifty-one million, two hundred forty-three thousand, two hundred twenty-three".