1217797440 has 112 divisors (see below), whose sum is σ = 3874495680. Its totient is φ = 324075520.

The previous prime is 1217797439. The next prime is 1217797463. The reversal of 1217797440 is 447977121.

It is a junction number, because it is equal to n+sod(n) for n = 1217797392 and 1217797401.

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 15 ways as a sum of consecutive naturals, for example, 614371 + ... + 616349.

Almost surely, 2^1217797440 is an apocalyptic number.

1217797440 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 1217797440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1937247840).

1217797440 is an abundant number, since it is smaller than the sum of its proper divisors (2656698240).

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

1217797440 is a wasteful number, since it uses less digits than its factorization.

1217797440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2640 (or 2630 counting only the distinct ones).

The product of its (nonzero) digits is 98784, while the sum is 42.

The square root of 1217797440 is about 34896.9545949213. The cubic root of 1217797440 is about 1067.8863097709.

The spelling of 1217797440 in words is "one billion, two hundred seventeen million, seven hundred ninety-seven thousand, four hundred forty".