21778082 has 8 divisors (see below), whose sum is σ = 33154896. Its totient is φ = 10726452.

The previous prime is 21778069. The next prime is 21778109. The reversal of 21778082 is 28087712.

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81128 + ... + 81395.

It is an arithmetic number, because the mean of its divisors is an integer number (4144362).

Almost surely, 2^21778082 is an apocalyptic number.

21778082 is a deficient number, since it is larger than the sum of its proper divisors (11376814).

21778082 is a wasteful number, since it uses less digits than its factorization.

21778082 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162592.

The product of its (nonzero) digits is 12544, while the sum is 35.

The square root of 21778082 is about 4666.6992617909. The cubic root of 21778082 is about 279.2585912864.

The spelling of 21778082 in words is "twenty-one million, seven hundred seventy-eight thousand, eighty-two".