1213111123 has 16 divisors (see below), whose sum is σ = 1408942080. Its totient is φ = 1023006816.

The previous prime is 1213111121. The next prime is 1213111139. The reversal of 1213111123 is 3211113121.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1213111123 - 2¹ = 1213111121 is a prime.

It is a super-2 number, since 2×1213111123² = 2943277193492642258, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1213111097 and 1213111106.

It is not an unprimeable number, because it can be changed into a prime (1213111121) 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, 158286 + ... + 165772.

It is an arithmetic number, because the mean of its divisors is an integer number (88058880).

Almost surely, 2^1213111123 is an apocalyptic number.

1213111123 is a deficient number, since it is larger than the sum of its proper divisors (195830957).

1213111123 is an equidigital number, since it uses as much as digits as its factorization.

1213111123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7866.

The product of its digits is 36, while the sum is 16.

The square root of 1213111123 is about 34829.7448023956. The cubic root of 1213111123 is about 1066.5147387891.

Adding to 1213111123 its reverse (3211113121), we get a palindrome (4424224244).

The spelling of 1213111123 in words is "one billion, two hundred thirteen million, one hundred eleven thousand, one hundred twenty-three".