21478336 has 28 divisors (see below), whose sum is σ = 46497240. Its totient is φ = 9762560.

The previous prime is 21478333. The next prime is 21478337. The reversal of 21478336 is 63387412.

It is a happy number.

It is a super-2 number, since 2×21478336² = 922637834657792, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21478333) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 14551 + ... + 15958.

Almost surely, 2^21478336 is an apocalyptic number.

It is an amenable number.

21478336 is an abundant number, since it is smaller than the sum of its proper divisors (25018904).

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

21478336 is a wasteful number, since it uses less digits than its factorization.

21478336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30532 (or 30522 counting only the distinct ones).

The product of its digits is 24192, while the sum is 34.

The square root of 21478336 is about 4634.4725697753. The cubic root of 21478336 is about 277.9714616254.

The spelling of 21478336 in words is "twenty-one million, four hundred seventy-eight thousand, three hundred thirty-six".