21347373 has 4 divisors (see below), whose sum is σ = 28463168. Its totient is φ = 14231580.

The previous prime is 21347371. The next prime is 21347419. The reversal of 21347373 is 37374312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 21347373 - 2¹ = 21347371 is a prime.

It is a super-2 number, since 2×21347373² = 911420668002258, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21347373.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21347371) 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 3 ways as a sum of consecutive naturals, for example, 3557893 + ... + 3557898.

It is an arithmetic number, because the mean of its divisors is an integer number (7115792).

Almost surely, 2^21347373 is an apocalyptic number.

It is an amenable number.

21347373 is a deficient number, since it is larger than the sum of its proper divisors (7115795).

21347373 is an equidigital number, since it uses as much as digits as its factorization.

21347373 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7115794.

The product of its digits is 10584, while the sum is 30.

The square root of 21347373 is about 4620.3217420435. The cubic root of 21347373 is about 277.4053374058.

It can be divided in two parts, 213 and 47373, that added together give a triangular number (47586 = T₃₀₈).

The spelling of 21347373 in words is "twenty-one million, three hundred forty-seven thousand, three hundred seventy-three".