82021111 has 4 divisors (see below), whose sum is σ = 82524472. Its totient is φ = 81517752.

The previous prime is 82021109. The next prime is 82021123. The reversal of 82021111 is 11112028.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 82021111 - 2¹ = 82021109 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (82021211) 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, 251436 + ... + 251761.

It is an arithmetic number, because the mean of its divisors is an integer number (20631118).

Almost surely, 2^82021111 is an apocalyptic number.

82021111 is a deficient number, since it is larger than the sum of its proper divisors (503361).

82021111 is a wasteful number, since it uses less digits than its factorization.

82021111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 503360.

The product of its (nonzero) digits is 32, while the sum is 16.

The square root of 82021111 is about 9056.5507230954. The cubic root of 82021111 is about 434.4854284464.

Adding to 82021111 its reverse (11112028), we get a palindrome (93133139).

The spelling of 82021111 in words is "eighty-two million, twenty-one thousand, one hundred eleven".