21340173 has 8 divisors (see below), whose sum is σ = 29951200. Its totient is φ = 13477968.

The previous prime is 21340171. The next prime is 21340177. The reversal of 21340173 is 37104312.

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

It is not a de Polignac number, because 21340173 - 2¹ = 21340171 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21340171) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 187138 + ... + 187251.

It is an arithmetic number, because the mean of its divisors is an integer number (3743900).

Almost surely, 2^21340173 is an apocalyptic number.

It is an amenable number.

21340173 is a deficient number, since it is larger than the sum of its proper divisors (8611027).

21340173 is a wasteful number, since it uses less digits than its factorization.

21340173 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 374411.

The product of its (nonzero) digits is 504, while the sum is 21.

The square root of 21340173 is about 4619.5425098163. The cubic root of 21340173 is about 277.3741463232.

Adding to 21340173 its reverse (37104312), we get a palindrome (58444485).

The spelling of 21340173 in words is "twenty-one million, three hundred forty thousand, one hundred seventy-three".