1217112720 has 80 divisors (see below), whose sum is σ = 3783186432. Its totient is φ = 323691520.

The previous prime is 1217112719. The next prime is 1217112733. The reversal of 1217112720 is 272117121.

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

It is a super-3 number, since 3×1217112720³ (a number of 28 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85300 + ... + 98540.

Almost surely, 2^1217112720 is an apocalyptic number.

1217112720 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 1217112720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1891593216).

1217112720 is an abundant number, since it is smaller than the sum of its proper divisors (2566073712).

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

1217112720 is a wasteful number, since it uses less digits than its factorization.

1217112720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13640 (or 13634 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 24.

The square root of 1217112720 is about 34887.1426173024. The cubic root of 1217112720 is about 1067.6861286419.

Adding to 1217112720 its reverse (272117121), we get a palindrome (1489229841).

The spelling of 1217112720 in words is "one billion, two hundred seventeen million, one hundred twelve thousand, seven hundred twenty".