21771022 has 64 divisors (see below), whose sum is σ = 42747264. Its totient is φ = 8087040.

The previous prime is 21771019. The next prime is 21771031. The reversal of 21771022 is 22017712.

It is a junction number, because it is equal to n+sod(n) for n = 21770984 and 21771002.

It is a congruent number.

It is an unprimeable number.

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 in 31 ways as a sum of consecutive naturals, for example, 356872 + ... + 356932.

It is an arithmetic number, because the mean of its divisors is an integer number (667926).

Almost surely, 2^21771022 is an apocalyptic number.

21771022 is a deficient number, since it is larger than the sum of its proper divisors (20976242).

21771022 is a wasteful number, since it uses less digits than its factorization.

21771022 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173.

The product of its (nonzero) digits is 392, while the sum is 22.

The square root of 21771022 is about 4665.9427771888. The cubic root of 21771022 is about 279.2284114212.

Adding to 21771022 its reverse (22017712), we get a palindrome (43788734).

The spelling of 21771022 in words is "twenty-one million, seven hundred seventy-one thousand, twenty-two".