21713841 has 12 divisors (see below), whose sum is σ = 31554432. Its totient is φ = 14388216.

The previous prime is 21713833. The next prime is 21713843. The reversal of 21713841 is 14831712.

It is not a de Polignac number, because 21713841 - 2³ = 21713833 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21713843) 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 11 ways as a sum of consecutive naturals, for example, 5721 + ... + 8726.

It is an arithmetic number, because the mean of its divisors is an integer number (2629536).

Almost surely, 2^21713841 is an apocalyptic number.

It is an amenable number.

21713841 is a deficient number, since it is larger than the sum of its proper divisors (9840591).

21713841 is a wasteful number, since it uses less digits than its factorization.

21713841 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14620 (or 14617 counting only the distinct ones).

The product of its digits is 1344, while the sum is 27.

The square root of 21713841 is about 4659.8112622723. The cubic root of 21713841 is about 278.9837351292.

The spelling of 21713841 in words is "twenty-one million, seven hundred thirteen thousand, eight hundred forty-one".