1213115540 has 192 divisors, whose sum is σ = 3266457600. Its totient is φ = 375943680.

The previous prime is 1213115513. The next prime is 1213115551. The reversal of 1213115540 is 455113121.

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 63 ways as a sum of consecutive naturals, for example, 5439869 + ... + 5440091.

It is an arithmetic number, because the mean of its divisors is an integer number (17012800).

Almost surely, 2^1213115540 is an apocalyptic number.

1213115540 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 1213115540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1633228800).

1213115540 is an abundant number, since it is smaller than the sum of its proper divisors (2053342060).

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

1213115540 is a wasteful number, since it uses less digits than its factorization.

1213115540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 327 (or 311 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 23.

The square root of 1213115540 is about 34829.8082107840. The cubic root of 1213115540 is about 1066.5160331992.

Adding to 1213115540 its reverse (455113121), we get a palindrome (1668228661).

The spelling of 1213115540 in words is "one billion, two hundred thirteen million, one hundred fifteen thousand, five hundred forty".