21706148 has 12 divisors (see below), whose sum is σ = 38128860. Its totient is φ = 10812192.

The previous prime is 21706133. The next prime is 21706177. The reversal of 21706148 is 84160712.

It can be written as a sum of positive squares in 2 ways, for example, as 13191424 + 8514724 = 3632^2 + 2918^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21706148.

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, 9011 + ... + 11162.

It is an arithmetic number, because the mean of its divisors is an integer number (3177405).

Almost surely, 2^21706148 is an apocalyptic number.

It is an amenable number.

21706148 is a deficient number, since it is larger than the sum of its proper divisors (16422712).

21706148 is a wasteful number, since it uses less digits than its factorization.

21706148 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20446 (or 20444 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 21706148 is about 4658.9857265289. The cubic root of 21706148 is about 278.9507841743.

The spelling of 21706148 in words is "twenty-one million, seven hundred six thousand, one hundred forty-eight".