21101012 has 24 divisors (see below), whose sum is σ = 39299904. Its totient is φ = 9878912.

The previous prime is 21100999. The next prime is 21101027. The reversal of 21101012 is 21010112.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14753 + ... + 16119.

It is an arithmetic number, because the mean of its divisors is an integer number (1637496).

Almost surely, 2^21101012 is an apocalyptic number.

It is an amenable number.

21101012 is a deficient number, since it is larger than the sum of its proper divisors (18198892).

21101012 is a wasteful number, since it uses less digits than its factorization.

21101012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1615 (or 1613 counting only the distinct ones).

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

The square root of 21101012 is about 4593.5837861086. The cubic root of 21101012 is about 276.3340665369.

Adding to 21101012 its reverse (21010112), we get a palindrome (42111124).

The spelling of 21101012 in words is "twenty-one million, one hundred one thousand, twelve".