1221132120 has 64 divisors (see below), whose sum is σ = 3945201120. Its totient is φ = 300585984.

The previous prime is 1221132113. The next prime is 1221132131. The reversal of 1221132120 is 212311221.

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 1221132120.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 389829 + ... + 392948.

Almost surely, 2^1221132120 is an apocalyptic number.

1221132120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221132120 is an abundant number, since it is smaller than the sum of its proper divisors (2724069000).

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

1221132120 is a wasteful number, since it uses less digits than its factorization.

1221132120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 782804 (or 782800 counting only the distinct ones).

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

The square root of 1221132120 is about 34944.7008858282. The cubic root of 1221132120 is about 1068.8601481495.

Adding to 1221132120 its reverse (212311221), we get a palindrome (1433443341).

The spelling of 1221132120 in words is "one billion, two hundred twenty-one million, one hundred thirty-two thousand, one hundred twenty".