21257896 has 16 divisors (see below), whose sum is σ = 43482240. Its totient is φ = 9662640.

The previous prime is 21257893. The next prime is 21257923. The reversal of 21257896 is 69875212.

It is not an unprimeable number, because it can be changed into a prime (21257893) 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 3 ways as a sum of consecutive naturals, for example, 120696 + ... + 120871.

It is an arithmetic number, because the mean of its divisors is an integer number (2717640).

Almost surely, 2^21257896 is an apocalyptic number.

It is an amenable number.

21257896 is an abundant number, since it is smaller than the sum of its proper divisors (22224344).

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

21257896 is a wasteful number, since it uses less digits than its factorization.

21257896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 241584 (or 241580 counting only the distinct ones).

The product of its digits is 60480, while the sum is 40.

The square root of 21257896 is about 4610.6285905503. The cubic root of 21257896 is about 277.0172153671.

The spelling of 21257896 in words is "twenty-one million, two hundred fifty-seven thousand, eight hundred ninety-six".