82921666 has 4 divisors (see below), whose sum is σ = 124382502. Its totient is φ = 41460832.

The previous prime is 82921661. The next prime is 82921667. The reversal of 82921666 is 66612928.

It is a happy number.

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

It can be written as a sum of positive squares in only one way, i.e., 59737441 + 23184225 = 7729^2 + 4815^2 .

It is not an unprimeable number, because it can be changed into a prime (82921661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20730415 + ... + 20730418.

Almost surely, 2^82921666 is an apocalyptic number.

82921666 is a deficient number, since it is larger than the sum of its proper divisors (41460836).

82921666 is a wasteful number, since it uses less digits than its factorization.

82921666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41460835.

The product of its digits is 62208, while the sum is 40.

The square root of 82921666 is about 9106.1334275311. The cubic root of 82921666 is about 436.0697956608.

The spelling of 82921666 in words is "eighty-two million, nine hundred twenty-one thousand, six hundred sixty-six".