21749383 has 4 divisors (see below), whose sum is σ = 22451008. Its totient is φ = 21047760.

The previous prime is 21749353. The next prime is 21749419. The reversal of 21749383 is 38394712.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21749383 - 2⁹ = 21748871 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 (21749323) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 350766 + ... + 350827.

It is an arithmetic number, because the mean of its divisors is an integer number (5612752).

Almost surely, 2^21749383 is an apocalyptic number.

21749383 is a deficient number, since it is larger than the sum of its proper divisors (701625).

21749383 is an equidigital number, since it uses as much as digits as its factorization.

21749383 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 701624.

The product of its digits is 36288, while the sum is 37.

The square root of 21749383 is about 4663.6233767319. The cubic root of 21749383 is about 279.1358690413.

It can be divided in two parts, 2 and 1749383, that added together give a triangular number (1749385 = T₁₈₇₀).

The spelling of 21749383 in words is "twenty-one million, seven hundred forty-nine thousand, three hundred eighty-three".