21090110 has 8 divisors (see below), whose sum is σ = 37962216. Its totient is φ = 8436040.

The previous prime is 21090109. The next prime is 21090119. The reversal of 21090110 is 1109012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21090119) 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, 1054496 + ... + 1054515.

It is an arithmetic number, because the mean of its divisors is an integer number (4745277).

Almost surely, 2^21090110 is an apocalyptic number.

21090110 is a deficient number, since it is larger than the sum of its proper divisors (16872106).

21090110 is a wasteful number, since it uses less digits than its factorization.

21090110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2109018.

The product of its (nonzero) digits is 18, while the sum is 14.

The square root of 21090110 is about 4592.3969776142. The cubic root of 21090110 is about 276.2864682990.

Adding to 21090110 its reverse (1109012), we get a palindrome (22199122).

The spelling of 21090110 in words is "twenty-one million, ninety thousand, one hundred ten".