21478882 has 4 divisors (see below), whose sum is σ = 32218326. Its totient is φ = 10739440.

The previous prime is 21478867. The next prime is 21478883. The reversal of 21478882 is 28887412.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 12047841 + 9431041 = 3471^2 + 3071^2 .

It is a super-2 number, since 2×21478882² = 922684743939848, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21478883) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5369719 + ... + 5369722.

Almost surely, 2^21478882 is an apocalyptic number.

21478882 is a deficient number, since it is larger than the sum of its proper divisors (10739444).

21478882 is a wasteful number, since it uses less digits than its factorization.

21478882 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10739443.

The product of its digits is 57344, while the sum is 40.

The square root of 21478882 is about 4634.5314757805. The cubic root of 21478882 is about 277.9738170396.

The spelling of 21478882 in words is "twenty-one million, four hundred seventy-eight thousand, eight hundred eighty-two".