21741687 has 12 divisors (see below), whose sum is σ = 34259784. Its totient is φ = 13176720.

The previous prime is 21741679. The next prime is 21741689. The reversal of 21741687 is 78614712.

It is not a de Polignac number, because 21741687 - 2³ = 21741679 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21741689) 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, 109708 + ... + 109905.

It is an arithmetic number, because the mean of its divisors is an integer number (2854982).

Almost surely, 2^21741687 is an apocalyptic number.

21741687 is a deficient number, since it is larger than the sum of its proper divisors (12518097).

21741687 is a wasteful number, since it uses less digits than its factorization.

21741687 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219630 (or 219627 counting only the distinct ones).

The product of its digits is 18816, while the sum is 36.

The square root of 21741687 is about 4662.7981942177. The cubic root of 21741687 is about 279.1029411635.

The spelling of 21741687 in words is "twenty-one million, seven hundred forty-one thousand, six hundred eighty-seven".