82218981 has 16 divisors (see below), whose sum is σ = 120939840. Its totient is φ = 49361280.

The previous prime is 82218979. The next prime is 82218989. The reversal of 82218981 is 18981228.

It is not a de Polignac number, because 82218981 - 2¹ = 82218979 is a prime.

It is a super-2 number, since 2×82218981² = 13519921673356722, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82218989) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24111 + ... + 27308.

It is an arithmetic number, because the mean of its divisors is an integer number (7558740).

Almost surely, 2^82218981 is an apocalyptic number.

It is an amenable number.

82218981 is a deficient number, since it is larger than the sum of its proper divisors (38720859).

82218981 is a wasteful number, since it uses less digits than its factorization.

82218981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51476.

The product of its digits is 18432, while the sum is 39.

The square root of 82218981 is about 9067.4682795144. The cubic root of 82218981 is about 434.8345360917.

The spelling of 82218981 in words is "eighty-two million, two hundred eighteen thousand, nine hundred eighty-one".