21123896 has 32 divisors (see below), whose sum is σ = 43046400. Its totient is φ = 9681120.

The previous prime is 21123887. The next prime is 21123899. The reversal of 21123896 is 69832112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21123899) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2471 + ... + 6953.

It is an arithmetic number, because the mean of its divisors is an integer number (1345200).

Almost surely, 2^21123896 is an apocalyptic number.

It is an amenable number.

21123896 is an abundant number, since it is smaller than the sum of its proper divisors (21922504).

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

21123896 is a wasteful number, since it uses less digits than its factorization.

21123896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4539 (or 4535 counting only the distinct ones).

The product of its digits is 5184, while the sum is 32.

The square root of 21123896 is about 4596.0739767763. The cubic root of 21123896 is about 276.4339250045.

The spelling of 21123896 in words is "twenty-one million, one hundred twenty-three thousand, eight hundred ninety-six".