21144955 has 8 divisors (see below), whose sum is σ = 27325872. Its totient is φ = 15614688.

The previous prime is 21144953. The next prime is 21144989. The reversal of 21144955 is 55944112.

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

It is a cyclic number.

It is not a de Polignac number, because 21144955 - 2¹ = 21144953 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21144953) by changing a digit.

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 in 7 ways as a sum of consecutive naturals, for example, 162589 + ... + 162718.

It is an arithmetic number, because the mean of its divisors is an integer number (3415734).

Almost surely, 2^21144955 is an apocalyptic number.

21144955 is a deficient number, since it is larger than the sum of its proper divisors (6180917).

21144955 is a wasteful number, since it uses less digits than its factorization.

21144955 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 325325.

The product of its digits is 7200, while the sum is 31.

The square root of 21144955 is about 4598.3643831258. The cubic root of 21144955 is about 276.5257560535.

The spelling of 21144955 in words is "twenty-one million, one hundred forty-four thousand, nine hundred fifty-five".