20661008 has 10 divisors (see below), whose sum is σ = 40030734. Its totient is φ = 10330496.

The previous prime is 20660993. The next prime is 20661013. The reversal of 20661008 is 80016602.

It can be written as a sum of positive squares in only one way, i.e., 18386944 + 2274064 = 4288^2 + 1508^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 645641 + ... + 645672.

Almost surely, 2^20661008 is an apocalyptic number.

It is an amenable number.

20661008 is a deficient number, since it is larger than the sum of its proper divisors (19369726).

20661008 is a wasteful number, since it uses less digits than its factorization.

20661008 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1291321 (or 1291315 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 20661008 is about 4545.4381526977. The cubic root of 20661008 is about 274.3998283027.

The spelling of 20661008 in words is "twenty million, six hundred sixty-one thousand, eight".