1211921120 has 24 divisors (see below), whose sum is σ = 2863164024. Its totient is φ = 484768384.

The previous prime is 1211921089. The next prime is 1211921131. The reversal of 1211921120 is 211291121.

It is a super-2 number, since 2×1211921120² = 2937505602204108800, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 1211921092 and 1211921101.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3787094 + ... + 3787413.

It is an arithmetic number, because the mean of its divisors is an integer number (119298501).

Almost surely, 2^1211921120 is an apocalyptic number.

1211921120 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211921120 is an abundant number, since it is smaller than the sum of its proper divisors (1651242904).

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

1211921120 is an equidigital number, since it uses as much as digits as its factorization.

1211921120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7574522 (or 7574514 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 20.

The square root of 1211921120 is about 34812.6574682255. The cubic root of 1211921120 is about 1066.1658916708.

The spelling of 1211921120 in words is "one billion, two hundred eleven million, nine hundred twenty-one thousand, one hundred twenty".