21741645 has 8 divisors (see below), whose sum is σ = 34786656. Its totient is φ = 11595536.

The previous prime is 21741641. The next prime is 21741649. The reversal of 21741645 is 54614712.

It is an interprime number because it is at equal distance from previous prime (21741641) and next prime (21741649).

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 21741645 - 2² = 21741641 is a prime.

It is a super-3 number, since 3×21741645³ (a number of 23 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21741641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 724707 + ... + 724736.

It is an arithmetic number, because the mean of its divisors is an integer number (4348332).

Almost surely, 2^21741645 is an apocalyptic number.

It is an amenable number.

21741645 is a deficient number, since it is larger than the sum of its proper divisors (13045011).

21741645 is a wasteful number, since it uses less digits than its factorization.

21741645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1449451.

The product of its digits is 6720, while the sum is 30.

The square root of 21741645 is about 4662.7936904821. The cubic root of 21741645 is about 279.1027614422.

The spelling of 21741645 in words is "twenty-one million, seven hundred forty-one thousand, six hundred forty-five".