21771104 has 12 divisors (see below), whose sum is σ = 42861924. Its totient is φ = 10885536.

The previous prime is 21771097. The next prime is 21771121. The reversal of 21771104 is 40117712.

It is a self number, because there is not a number n which added to its sum of digits gives 21771104.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340142 + ... + 340205.

It is an arithmetic number, because the mean of its divisors is an integer number (3571827).

Almost surely, 2^21771104 is an apocalyptic number.

It is an amenable number.

21771104 is a deficient number, since it is larger than the sum of its proper divisors (21090820).

21771104 is an equidigital number, since it uses as much as digits as its factorization.

21771104 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 680357 (or 680349 counting only the distinct ones).

The product of its (nonzero) digits is 392, while the sum is 23.

The square root of 21771104 is about 4665.9515642578. The cubic root of 21771104 is about 279.2287619896.

Adding to 21771104 its reverse (40117712), we get a palindrome (61888816).

The spelling of 21771104 in words is "twenty-one million, seven hundred seventy-one thousand, one hundred four".