1217881 has 8 divisors (see below), whose sum is σ = 1465280. Its totient is φ = 988848.

The previous prime is 1217861. The next prime is 1217893. The reversal of 1217881 is 1887121.

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

It is not a de Polignac number, because 1217881 - 2⁷ = 1217753 is a prime.

It is a super-2 number, since 2×1217881² = 2966468260322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1217831) 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, 4446 + ... + 4711.

It is an arithmetic number, because the mean of its divisors is an integer number (183160).

2^1217881 is an apocalyptic number.

It is an amenable number.

1217881 is a deficient number, since it is larger than the sum of its proper divisors (247399).

1217881 is an equidigital number, since it uses as much as digits as its factorization.

1217881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9183.

The product of its digits is 896, while the sum is 28.

The square root of 1217881 is about 1103.5764586108. The cubic root of 1217881 is about 106.7910733794.

The spelling of 1217881 in words is "one million, two hundred seventeen thousand, eight hundred eighty-one".