20891606 has 16 divisors (see below), whose sum is σ = 34079616. Its totient is φ = 9565056.

The previous prime is 20891603. The next prime is 20891639. The reversal of 20891606 is 60619802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20891603) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7046 + ... + 9561.

It is an arithmetic number, because the mean of its divisors is an integer number (2129976).

Almost surely, 2^20891606 is an apocalyptic number.

20891606 is a deficient number, since it is larger than the sum of its proper divisors (13188010).

20891606 is a wasteful number, since it uses less digits than its factorization.

20891606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16663.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 20891606 is about 4570.7336391437. The cubic root of 20891606 is about 275.4169147230.

The spelling of 20891606 in words is "twenty million, eight hundred ninety-one thousand, six hundred six".