1221123120 has 120 divisors (see below), whose sum is σ = 4403561904. Its totient is φ = 279111168.

The previous prime is 1221123109. The next prime is 1221123149. The reversal of 1221123120 is 213211221.

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-2 number, since 2×1221123120² = 2982283348397068800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 1221123120.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 40159 + ... + 63678.

Almost surely, 2^1221123120 is an apocalyptic number.

1221123120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221123120 is an abundant number, since it is smaller than the sum of its proper divisors (3182438784).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221123120 is a wasteful number, since it uses less digits than its factorization.

1221123120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 103867 (or 103854 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 1221123120 is about 34944.5721107013. The cubic root of 1221123120 is about 1068.8575222352.

Adding to 1221123120 its reverse (213211221), we get a palindrome (1434334341).

The spelling of 1221123120 in words is "one billion, two hundred twenty-one million, one hundred twenty-three thousand, one hundred twenty".