21047708 has 18 divisors (see below), whose sum is σ = 40487328. Its totient is φ = 9566920.

The previous prime is 21047671. The next prime is 21047713. The reversal of 21047708 is 80774012.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 21260 + ... + 22227.

It is an arithmetic number, because the mean of its divisors is an integer number (2249296).

Almost surely, 2^21047708 is an apocalyptic number.

It is an amenable number.

21047708 is a deficient number, since it is larger than the sum of its proper divisors (19439620).

21047708 is a wasteful number, since it uses less digits than its factorization.

21047708 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43513 (or 43500 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 29.

The square root of 21047708 is about 4587.7781114609. The cubic root of 21047708 is about 276.1011846322.

The spelling of 21047708 in words is "twenty-one million, forty-seven thousand, seven hundred eight".