21161606 has 8 divisors (see below), whose sum is σ = 31764744. Its totient is φ = 10573360.

The previous prime is 21161603. The next prime is 21161627. The reversal of 21161606 is 60616112.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21161603) by changing a digit.

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, 1061 + ... + 6591.

It is an arithmetic number, because the mean of its divisors is an integer number (3970593).

Almost surely, 2^21161606 is an apocalyptic number.

21161606 is a deficient number, since it is larger than the sum of its proper divisors (10603138).

21161606 is a wasteful number, since it uses less digits than its factorization.

21161606 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7446.

The product of its (nonzero) digits is 432, while the sum is 23.

The square root of 21161606 is about 4600.1745619052. The cubic root of 21161606 is about 276.5983221774.

Adding to 21161606 its reverse (60616112), we get a palindrome (81777718).

The spelling of 21161606 in words is "twenty-one million, one hundred sixty-one thousand, six hundred six".