21482778 has 8 divisors (see below), whose sum is σ = 42965568. Its totient is φ = 7160924.

The previous prime is 21482767. The next prime is 21482779. The reversal of 21482778 is 87728412.

It is a sphenic number, since it is the product of 3 distinct primes.

21482778 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (21482779) 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, 1790226 + ... + 1790237.

It is an arithmetic number, because the mean of its divisors is an integer number (5370696).

Almost surely, 2^21482778 is an apocalyptic number.

21482778 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21482778 is a wasteful number, since it uses less digits than its factorization.

21482778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3580468.

The product of its digits is 50176, while the sum is 39.

The square root of 21482778 is about 4634.9517796844. The cubic root of 21482778 is about 277.9906230124.

The spelling of 21482778 in words is "twenty-one million, four hundred eighty-two thousand, seven hundred seventy-eight".