21420896 has 24 divisors (see below), whose sum is σ = 48197520. Its totient is φ = 9180288.

The previous prime is 21420887. The next prime is 21420941. The reversal of 21420896 is 69802412.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47591 + ... + 48038.

It is an arithmetic number, because the mean of its divisors is an integer number (2008230).

Almost surely, 2^21420896 is an apocalyptic number.

It is an amenable number.

21420896 is an abundant number, since it is smaller than the sum of its proper divisors (26776624).

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

21420896 is an equidigital number, since it uses as much as digits as its factorization.

21420896 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95646 (or 95638 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 32.

The square root of 21420896 is about 4628.2713835729. The cubic root of 21420896 is about 277.7234452786.

It can be divided in two parts, 214 and 20896, that multiplied together give a palindrome (4471744).

The spelling of 21420896 in words is "twenty-one million, four hundred twenty thousand, eight hundred ninety-six".