21749413 has 8 divisors (see below), whose sum is σ = 24969728. Its totient is φ = 18557424.

The previous prime is 21749353. The next prime is 21749419. The reversal of 21749413 is 31494712.

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 21749413 - 2¹⁷ = 21618341 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21749419) 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, 5406 + ... + 8527.

It is an arithmetic number, because the mean of its divisors is an integer number (3121216).

Almost surely, 2^21749413 is an apocalyptic number.

It is an amenable number.

21749413 is a deficient number, since it is larger than the sum of its proper divisors (3220315).

21749413 is a wasteful number, since it uses less digits than its factorization.

21749413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14163.

The product of its digits is 6048, while the sum is 31.

The square root of 21749413 is about 4663.6265931140. The cubic root of 21749413 is about 279.1359973832.

The spelling of 21749413 in words is "twenty-one million, seven hundred forty-nine thousand, four hundred thirteen".