21052173 has 8 divisors (see below), whose sum is σ = 29037600. Its totient is φ = 13550768.

The previous prime is 21052169. The next prime is 21052177. The reversal of 21052173 is 37125012.

It is an interprime number because it is at equal distance from previous prime (21052169) and next prime (21052177).

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 21052173 - 2² = 21052169 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21052177) 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 7 ways as a sum of consecutive naturals, for example, 120903 + ... + 121076.

It is an arithmetic number, because the mean of its divisors is an integer number (3629700).

Almost surely, 2^21052173 is an apocalyptic number.

It is an amenable number.

21052173 is a deficient number, since it is larger than the sum of its proper divisors (7985427).

21052173 is a wasteful number, since it uses less digits than its factorization.

21052173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 242011.

The product of its (nonzero) digits is 420, while the sum is 21.

The square root of 21052173 is about 4588.2647046569. The cubic root of 21052173 is about 276.1207070211.

Adding to 21052173 its reverse (37125012), we get a palindrome (58177185).

It can be divided in two parts, 2105 and 2173, that added together give a triangular number (4278 = T₉₂).

The spelling of 21052173 in words is "twenty-one million, fifty-two thousand, one hundred seventy-three".