82218257 has 4 divisors (see below), whose sum is σ = 89692656. Its totient is φ = 74743860.

The previous prime is 82218251. The next prime is 82218259. The reversal of 82218257 is 75281228.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 82218257 - 2¹² = 82214161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (82218251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3737183 + ... + 3737204.

It is an arithmetic number, because the mean of its divisors is an integer number (22423164).

Almost surely, 2^82218257 is an apocalyptic number.

It is an amenable number.

82218257 is a deficient number, since it is larger than the sum of its proper divisors (7474399).

82218257 is a wasteful number, since it uses less digits than its factorization.

82218257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7474398.

The product of its digits is 17920, while the sum is 35.

The square root of 82218257 is about 9067.4283564856. The cubic root of 82218257 is about 434.8332597395.

The spelling of 82218257 in words is "eighty-two million, two hundred eighteen thousand, two hundred fifty-seven".