21056618 has 8 divisors (see below), whose sum is σ = 34456320. Its totient is φ = 9571180.

The previous prime is 21056597. The next prime is 21056653. The reversal of 21056618 is 81665012.

It is a happy number.

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

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 478538 + ... + 478581.

It is an arithmetic number, because the mean of its divisors is an integer number (4307040).

Almost surely, 2^21056618 is an apocalyptic number.

21056618 is a deficient number, since it is larger than the sum of its proper divisors (13399702).

21056618 is a wasteful number, since it uses less digits than its factorization.

21056618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 957132.

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 21056618 is about 4588.7490670116. The cubic root of 21056618 is about 276.1401392221.

The spelling of 21056618 in words is "twenty-one million, fifty-six thousand, six hundred eighteen".