21012110 has 64 divisors (see below), whose sum is σ = 46669824. Its totient is φ = 6652800.

The previous prime is 21012091. The next prime is 21012127. The reversal of 21012110 is 1121012.

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, 49700 + ... + 50120.

It is an arithmetic number, because the mean of its divisors is an integer number (729216).

Almost surely, 2^21012110 is an apocalyptic number.

21012110 is an abundant number, since it is smaller than the sum of its proper divisors (25657714).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21012110 is a wasteful number, since it uses less digits than its factorization.

21012110 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 489.

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

The square root of 21012110 is about 4583.8968138474. The cubic root of 21012110 is about 275.9454401009.

Adding to 21012110 its reverse (1121012), we get a palindrome (22133122).

The spelling of 21012110 in words is "twenty-one million, twelve thousand, one hundred ten".