21749741 has 8 divisors (see below), whose sum is σ = 23773344. Its totient is φ = 19776240.

The previous prime is 21749729. The next prime is 21749759. The reversal of 21749741 is 14794712.

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 21749741 - 2⁶ = 21749677 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 (21746741) 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, 11615 + ... + 13356.

It is an arithmetic number, because the mean of its divisors is an integer number (2971668).

Almost surely, 2^21749741 is an apocalyptic number.

It is an amenable number.

21749741 is a deficient number, since it is larger than the sum of its proper divisors (2023603).

21749741 is a wasteful number, since it uses less digits than its factorization.

21749741 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25051.

The product of its digits is 14112, while the sum is 35.

The square root of 21749741 is about 4663.6617587471. The cubic root of 21749741 is about 279.1374005805.

The spelling of 21749741 in words is "twenty-one million, seven hundred forty-nine thousand, seven hundred forty-one".