21387896 has 32 divisors (see below), whose sum is σ = 41413680. Its totient is φ = 10348800.

The previous prime is 21387893. The next prime is 21387929. The reversal of 21387896 is 69878312.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21387893) 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, 64451 + ... + 64781.

Almost surely, 2^21387896 is an apocalyptic number.

It is an amenable number.

21387896 is a deficient number, since it is larger than the sum of its proper divisors (20025784).

21387896 is a wasteful number, since it uses less digits than its factorization.

21387896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 575 (or 571 counting only the distinct ones).

The product of its digits is 145152, while the sum is 44.

The square root of 21387896 is about 4624.7049635625. The cubic root of 21387896 is about 277.5807561952.

The spelling of 21387896 in words is "twenty-one million, three hundred eighty-seven thousand, eight hundred ninety-six".