1213511320 has 64 divisors (see below), whose sum is σ = 3179373120. Its totient is φ = 408205824.

The previous prime is 1213511297. The next prime is 1213511381. The reversal of 1213511320 is 231153121.

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 15 ways as a sum of consecutive naturals, for example, 26047 + ... + 55726.

It is an arithmetic number, because the mean of its divisors is an integer number (49677705).

Almost surely, 2^1213511320 is an apocalyptic number.

1213511320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1213511320 is an abundant number, since it is smaller than the sum of its proper divisors (1965861800).

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

1213511320 is a wasteful number, since it uses less digits than its factorization.

1213511320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81844 (or 81840 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 1213511320 is about 34835.4893750612. The cubic root of 1213511320 is about 1066.6320045160.

Adding to 1213511320 its reverse (231153121), we get a palindrome (1444664441).

The spelling of 1213511320 in words is "one billion, two hundred thirteen million, five hundred eleven thousand, three hundred twenty".