1217840256 has 96 divisors (see below), whose sum is σ = 3513369600. Its totient is φ = 404915712.

The previous prime is 1217840249. The next prime is 1217840263. The reversal of 1217840256 is 6520487121.

It is an interprime number because it is at equal distance from previous prime (1217840249) and next prime (1217840263).

It is a tau number, because it is divible by the number of its divisors (96).

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 1217840256.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 550705 + ... + 552911.

It is an arithmetic number, because the mean of its divisors is an integer number (36597600).

Almost surely, 2^1217840256 is an apocalyptic number.

1217840256 is a gapful number since it is divisible by the number (16) 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 1217840256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1756684800).

1217840256 is an abundant number, since it is smaller than the sum of its proper divisors (2295529344).

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

1217840256 is a wasteful number, since it uses less digits than its factorization.

1217840256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2706 (or 2691 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 36.

The square root of 1217840256 is about 34897.5680528028. The cubic root of 1217840256 is about 1067.8988247379.

The spelling of 1217840256 in words is "one billion, two hundred seventeen million, eight hundred forty thousand, two hundred fifty-six".