21011896 has 16 divisors (see below), whose sum is σ = 39709440. Its totient is φ = 10422720.

The previous prime is 21011873. The next prime is 21011917. The reversal of 21011896 is 69811012.

It is a happy number.

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 3 ways as a sum of consecutive naturals, for example, 9325 + ... + 11356.

It is an arithmetic number, because the mean of its divisors is an integer number (2481840).

Almost surely, 2^21011896 is an apocalyptic number.

It is an amenable number.

21011896 is a deficient number, since it is larger than the sum of its proper divisors (18697544).

21011896 is a wasteful number, since it uses less digits than its factorization.

21011896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20814 (or 20810 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 21011896 is about 4583.8734712031. The cubic root of 21011896 is about 275.9445032995.

The spelling of 21011896 in words is "twenty-one million, eleven thousand, eight hundred ninety-six".