21871896 has 32 divisors (see below), whose sum is σ = 57058560. Its totient is φ = 6973472.

The previous prime is 21871849. The next prime is 21871903. The reversal of 21871896 is 69817812.

21871896 = T₁₄₄ + T₁₄₅ + ... + T₅₁₁.

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, 19260 + ... + 20363.

It is an arithmetic number, because the mean of its divisors is an integer number (1783080).

Almost surely, 2^21871896 is an apocalyptic number.

It is an amenable number.

21871896 is an abundant number, since it is smaller than the sum of its proper divisors (35186664).

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

21871896 is a wasteful number, since it uses less digits than its factorization.

21871896 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39655 (or 39651 counting only the distinct ones).

The product of its digits is 48384, while the sum is 42.

The square root of 21871896 is about 4676.7398901371. The cubic root of 21871896 is about 279.6590066642.

The spelling of 21871896 in words is "twenty-one million, eight hundred seventy-one thousand, eight hundred ninety-six".