21210110 has 8 divisors (see below), whose sum is σ = 38178216. Its totient is φ = 8484040.

The previous prime is 21210109. The next prime is 21210151. The reversal of 21210110 is 1101212.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1060496 + ... + 1060515.

It is an arithmetic number, because the mean of its divisors is an integer number (4772277).

Almost surely, 2^21210110 is an apocalyptic number.

21210110 is a deficient number, since it is larger than the sum of its proper divisors (16968106).

21210110 is a wasteful number, since it uses less digits than its factorization.

21210110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2121018.

The product of its (nonzero) digits is 4, while the sum is 8.

The square root of 21210110 is about 4605.4435182727. The cubic root of 21210110 is about 276.8094890078.

Adding to 21210110 its reverse (1101212), we get a palindrome (22311322).

The spelling of 21210110 in words is "twenty-one million, two hundred ten thousand, one hundred ten".