21601144 has 8 divisors (see below), whose sum is σ = 40502160. Its totient is φ = 10800568.

The previous prime is 21601121. The next prime is 21601171. The reversal of 21601144 is 44110612.

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (19) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 1350064 + ... + 1350079.

It is an arithmetic number, because the mean of its divisors is an integer number (5062770).

Almost surely, 2^21601144 is an apocalyptic number.

It is an amenable number.

21601144 is a deficient number, since it is larger than the sum of its proper divisors (18901016).

21601144 is a wasteful number, since it uses less digits than its factorization.

21601144 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2700149 (or 2700145 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 21601144 is about 4647.7030886235. The cubic root of 21601144 is about 278.5002465759.

Adding to 21601144 its reverse (44110612), we get a palindrome (65711756).

The spelling of 21601144 in words is "twenty-one million, six hundred one thousand, one hundred forty-four".