21478748 has 12 divisors (see below), whose sum is σ = 37884672. Its totient is φ = 10654560.

The previous prime is 21478741. The next prime is 21478781. The reversal of 21478748 is 84787412.

It is a happy number.

It is a super-2 number, since 2×21478748² = 922673231295008, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21478741) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20633 + ... + 21648.

It is an arithmetic number, because the mean of its divisors is an integer number (3157056).

Almost surely, 2^21478748 is an apocalyptic number.

It is an amenable number.

21478748 is a deficient number, since it is larger than the sum of its proper divisors (16405924).

21478748 is a wasteful number, since it uses less digits than its factorization.

21478748 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42412 (or 42410 counting only the distinct ones).

The product of its digits is 100352, while the sum is 41.

The square root of 21478748 is about 4634.5170190647. The cubic root of 21478748 is about 277.9732389746.

The spelling of 21478748 in words is "twenty-one million, four hundred seventy-eight thousand, seven hundred forty-eight".