21022618 has 8 divisors (see below), whose sum is σ = 31775040. Its totient is φ = 10430940.

The previous prime is 21022597. The next prime is 21022669. The reversal of 21022618 is 81622012.

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, 39858 + ... + 40381.

It is an arithmetic number, because the mean of its divisors is an integer number (3971880).

Almost surely, 2^21022618 is an apocalyptic number.

21022618 is a deficient number, since it is larger than the sum of its proper divisors (10752422).

21022618 is a wasteful number, since it uses less digits than its factorization.

21022618 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80372.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 21022618 is about 4585.0428569426. The cubic root of 21022618 is about 275.9914318561.

The spelling of 21022618 in words is "twenty-one million, twenty-two thousand, six hundred eighteen".