1221123423 has 16 divisors (see below), whose sum is σ = 1757500416. Its totient is φ = 749706720.

The previous prime is 1221123419. The next prime is 1221123427. The reversal of 1221123423 is 3243211221.

It is an interprime number because it is at equal distance from previous prime (1221123419) and next prime (1221123427).

It is not a de Polignac number, because 1221123423 - 2² = 1221123419 is a prime.

It is a super-2 number, since 2×1221123423² = 2982284828398473858, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1221123423.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221123427) 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, 19515 + ... + 53132.

It is an arithmetic number, because the mean of its divisors is an integer number (109843776).

Almost surely, 2^1221123423 is an apocalyptic number.

1221123423 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1221123423 is a deficient number, since it is larger than the sum of its proper divisors (536376993).

1221123423 is a wasteful number, since it uses less digits than its factorization.

1221123423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73094.

The product of its digits is 576, while the sum is 21.

The square root of 1221123423 is about 34944.5764461382. The cubic root of 1221123423 is about 1068.8576106412.

Adding to 1221123423 its reverse (3243211221), we get a palindrome (4464334644).

The spelling of 1221123423 in words is "one billion, two hundred twenty-one million, one hundred twenty-three thousand, four hundred twenty-three".