1211520320 has 56 divisors (see below), whose sum is σ = 2902756704. Its totient is φ = 481614336.

The previous prime is 1211520319. The next prime is 1211520353. The reversal of 1211520320 is 230251121.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40547 + ... + 63773.

Almost surely, 2^1211520320 is an apocalyptic number.

1211520320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1211520320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1451378352).

1211520320 is an abundant number, since it is smaller than the sum of its proper divisors (1691236384).

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

1211520320 is a wasteful number, since it uses less digits than its factorization.

1211520320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23407 (or 23397 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 1211520320 is about 34806.9004652813. The cubic root of 1211520320 is about 1066.0483465055.

Adding to 1211520320 its reverse (230251121), we get a palindrome (1441771441).

The spelling of 1211520320 in words is "one billion, two hundred eleven million, five hundred twenty thousand, three hundred twenty".