1223705551 has 4 divisors (see below), whose sum is σ = 1256778712. Its totient is φ = 1190632392.

The previous prime is 1223705459. The next prime is 1223705569. The reversal of 1223705551 is 1555073221.

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

It is a cyclic number.

It is not a de Polignac number, because 1223705551 - 2⁷ = 1223705423 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 (1223705591) 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, 16536525 + ... + 16536598.

It is an arithmetic number, because the mean of its divisors is an integer number (314194678).

Almost surely, 2^1223705551 is an apocalyptic number.

1223705551 is a deficient number, since it is larger than the sum of its proper divisors (33073161).

1223705551 is an equidigital number, since it uses as much as digits as its factorization.

1223705551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33073160.

The product of its (nonzero) digits is 10500, while the sum is 31.

The square root of 1223705551 is about 34981.5029837198. The cubic root of 1223705551 is about 1069.6104649552.

Adding to 1223705551 its reverse (1555073221), we get a palindrome (2778778772).

The spelling of 1223705551 in words is "one billion, two hundred twenty-three million, seven hundred five thousand, five hundred fifty-one".