21147708 has 12 divisors (see below), whose sum is σ = 49344680. Its totient is φ = 7049232.

The previous prime is 21147671. The next prime is 21147713. The reversal of 21147708 is 80774112.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 881143 + ... + 881166.

Almost surely, 2^21147708 is an apocalyptic number.

It is an amenable number.

21147708 is an abundant number, since it is smaller than the sum of its proper divisors (28196972).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21147708 is a wasteful number, since it uses less digits than its factorization.

21147708 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1762316 (or 1762314 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 30.

The square root of 21147708 is about 4598.6637189514. The cubic root of 21147708 is about 276.5377564316.

The spelling of 21147708 in words is "twenty-one million, one hundred forty-seven thousand, seven hundred eight".