20988866 has 8 divisors (see below), whose sum is σ = 32569020. Its totient is φ = 10132528.

The previous prime is 20988853. The next prime is 20988881. The reversal of 20988866 is 66888902.

It can be written as a sum of positive squares in 2 ways, for example, as 18361225 + 2627641 = 4285^2 + 1621^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 20988866.

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, 180881 + ... + 180996.

Almost surely, 2^20988866 is an apocalyptic number.

20988866 is a deficient number, since it is larger than the sum of its proper divisors (11580154).

20988866 is a wasteful number, since it uses less digits than its factorization.

20988866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 361908.

The product of its (nonzero) digits is 331776, while the sum is 47.

The square root of 20988866 is about 4581.3607148968. The cubic root of 20988866 is about 275.8436505077.

The spelling of 20988866 in words is "twenty million, nine hundred eighty-eight thousand, eight hundred sixty-six".