7881217 has 8 divisors (see below), whose sum is σ = 8440200. Its totient is φ = 7332864.

The previous prime is 7881193. The next prime is 7881221. The reversal of 7881217 is 7121887.

It can be written as a sum of positive squares in 4 ways, for example, as 3254416 + 4626801 = 1804^2 + 2151^2 .

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 7881217 - 2⁷ = 7881089 is a prime.

It is a super-2 number, since 2×7881217² = 124227162802178, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7881227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1092 + ... + 4117.

It is an arithmetic number, because the mean of its divisors is an integer number (1055025).

Almost surely, 2^7881217 is an apocalyptic number.

It is an amenable number.

7881217 is a deficient number, since it is larger than the sum of its proper divisors (558983).

7881217 is a wasteful number, since it uses less digits than its factorization.

7881217 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5315.

The product of its digits is 6272, while the sum is 34.

The square root of 7881217 is about 2807.3505303043. The cubic root of 7881217 is about 199.0052017529.

The spelling of 7881217 in words is "seven million, eight hundred eighty-one thousand, two hundred seventeen".