1217681 has 8 divisors (see below), whose sum is σ = 1272000. Its totient is φ = 1164240.

The previous prime is 1217677. The next prime is 1217683. The reversal of 1217681 is 1867121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1217681 - 2² = 1217677 is a prime.

It is a super-2 number, since 2×1217681² = 2965494035522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1217681.

It is not an unprimeable number, because it can be changed into a prime (1217683) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5666 + ... + 5876.

It is an arithmetic number, because the mean of its divisors is an integer number (159000).

2^1217681 is an apocalyptic number.

It is an amenable number.

1217681 is a deficient number, since it is larger than the sum of its proper divisors (54319).

1217681 is a wasteful number, since it uses less digits than its factorization.

1217681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 439.

The product of its digits is 672, while the sum is 26.

The square root of 1217681 is about 1103.4858404166. The cubic root of 1217681 is about 106.7852273283.

The spelling of 1217681 in words is "one million, two hundred seventeen thousand, six hundred eighty-one".