21478008 has 16 divisors (see below), whose sum is σ = 53695080. Its totient is φ = 7159328.

The previous prime is 21478007. The next prime is 21478049. The reversal of 21478008 is 80087412.

It is a super-2 number, since 2×21478008² = 922609655296128, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21478007) 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, 447435 + ... + 447482.

Almost surely, 2^21478008 is an apocalyptic number.

It is an amenable number.

21478008 is an abundant number, since it is smaller than the sum of its proper divisors (32217072).

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

21478008 is a wasteful number, since it uses less digits than its factorization.

21478008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 894926 (or 894922 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 30.

The square root of 21478008 is about 4634.4371826577. The cubic root of 21478008 is about 277.9700466322.

The spelling of 21478008 in words is "twenty-one million, four hundred seventy-eight thousand, eight".