20899666 has 4 divisors (see below), whose sum is σ = 31349502. Its totient is φ = 10449832.

The previous prime is 20899607. The next prime is 20899679. The reversal of 20899666 is 66699802.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 20894041 + 5625 = 4571^2 + 75^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5224915 + ... + 5224918.

Almost surely, 2^20899666 is an apocalyptic number.

20899666 is a deficient number, since it is larger than the sum of its proper divisors (10449836).

20899666 is a wasteful number, since it uses less digits than its factorization.

20899666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10449835.

The product of its (nonzero) digits is 279936, while the sum is 46.

The square root of 20899666 is about 4571.6152506527. The cubic root of 20899666 is about 275.4523288652.

The spelling of 20899666 in words is "twenty million, eight hundred ninety-nine thousand, six hundred sixty-six".