21051996 has 24 divisors (see below), whose sum is σ = 56138880. Its totient is φ = 6014832.

The previous prime is 21051991. The next prime is 21052039. The reversal of 21051996 is 69915012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21051991) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 125226 + ... + 125393.

It is an arithmetic number, because the mean of its divisors is an integer number (2339120).

Almost surely, 2^21051996 is an apocalyptic number.

It is an amenable number.

21051996 is an abundant number, since it is smaller than the sum of its proper divisors (35086884).

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

21051996 is a wasteful number, since it uses less digits than its factorization.

21051996 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 250633 (or 250631 counting only the distinct ones).

The product of its (nonzero) digits is 4860, while the sum is 33.

The square root of 21051996 is about 4588.2454162784. The cubic root of 21051996 is about 276.1199331738.

The spelling of 21051996 in words is "twenty-one million, fifty-one thousand, nine hundred ninety-six".