20406664 has 32 divisors (see below), whose sum is σ = 40786200. Its totient is φ = 9538560.

The previous prime is 20406641. The next prime is 20406667. The reversal of 20406664 is 46660402.

It can be written as a sum of positive squares in 4 ways, for example, as 14884164 + 5522500 = 3858^2 + 2350^2 .

It is not an unprimeable number, because it can be changed into a prime (20406667) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24202 + ... + 25030.

Almost surely, 2^20406664 is an apocalyptic number.

It is an amenable number.

20406664 is a deficient number, since it is larger than the sum of its proper divisors (20379536).

20406664 is a wasteful number, since it uses less digits than its factorization.

20406664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1033 (or 1029 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 28.

The square root of 20406664 is about 4517.3735732171. The cubic root of 20406664 is about 273.2691911095.

The spelling of 20406664 in words is "twenty million, four hundred six thousand, six hundred sixty-four".