1123212121 has 8 divisors (see below), whose sum is σ = 1127095200. Its totient is φ = 1119336960.

The previous prime is 1123212067. The next prime is 1123212127. The reversal of 1123212121 is 1212123211.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1123212121 - 2⁷ = 1123211993 is a prime.

It is a super-2 number, since 2×1123212121² = 2523210937522637282, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1123212095 and 1123212104.

It is not an unprimeable number, because it can be changed into a prime (1123212127) 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 7 ways as a sum of consecutive naturals, for example, 421090 + ... + 423748.

It is an arithmetic number, because the mean of its divisors is an integer number (140886900).

Almost surely, 2^1123212121 is an apocalyptic number.

It is an amenable number.

1123212121 is a deficient number, since it is larger than the sum of its proper divisors (3883079).

1123212121 is an equidigital number, since it uses as much as digits as its factorization.

1123212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3959.

The product of its digits is 48, while the sum is 16.

The square root of 1123212121 is about 33514.3569384823. The cubic root of 1123212121 is about 1039.4906655994.

Adding to 1123212121 its reverse (1212123211), we get a palindrome (2335335332).

The spelling of 1123212121 in words is "one billion, one hundred twenty-three million, two hundred twelve thousand, one hundred twenty-one".