1223123551 has 16 divisors (see below), whose sum is σ = 1330449120. Its totient is φ = 1117733760.

The previous prime is 1223123501. The next prime is 1223123591. The reversal of 1223123551 is 1553213221.

It is not a de Polignac number, because 1223123551 - 2⁹ = 1223123039 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1223123501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1206921 + ... + 1207933.

It is an arithmetic number, because the mean of its divisors is an integer number (83153070).

Almost surely, 2^1223123551 is an apocalyptic number.

1223123551 is a deficient number, since it is larger than the sum of its proper divisors (107325569).

1223123551 is a wasteful number, since it uses less digits than its factorization.

1223123551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1866.

The product of its digits is 1800, while the sum is 25.

The square root of 1223123551 is about 34973.1833123609. The cubic root of 1223123551 is about 1069.4408675096.

Adding to 1223123551 its reverse (1553213221), we get a palindrome (2776336772).

The spelling of 1223123551 in words is "one billion, two hundred twenty-three million, one hundred twenty-three thousand, five hundred fifty-one".