1217512240 has 80 divisors (see below), whose sum is σ = 3240149760. Its totient is φ = 416782080.

The previous prime is 1217512207. The next prime is 1217512243. The reversal of 1217512240 is 422157121.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (1217512243) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 479775 + ... + 482305.

It is an arithmetic number, because the mean of its divisors is an integer number (40501872).

Almost surely, 2^1217512240 is an apocalyptic number.

1217512240 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 1217512240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1620074880).

1217512240 is an abundant number, since it is smaller than the sum of its proper divisors (2022637520).

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

1217512240 is a wasteful number, since it uses less digits than its factorization.

1217512240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3410 (or 3404 counting only the distinct ones).

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 1217512240 is about 34892.8680391853. The cubic root of 1217512240 is about 1067.8029393230.

Adding to 1217512240 its reverse (422157121), we get a palindrome (1639669361).

The spelling of 1217512240 in words is "one billion, two hundred seventeen million, five hundred twelve thousand, two hundred forty".