20406663 has 6 divisors (see below), whose sum is σ = 29476304. Its totient is φ = 13604436.

The previous prime is 20406641. The next prime is 20406667. The reversal of 20406663 is 36660402.

It is not a de Polignac number, because 20406663 - 2¹³ = 20398471 is a prime.

It is a Duffinian number.

It is a congruent number.

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 (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1133695 + ... + 1133712.

Almost surely, 2^20406663 is an apocalyptic number.

20406663 is a deficient number, since it is larger than the sum of its proper divisors (9069641).

20406663 is a wasteful number, since it uses less digits than its factorization.

20406663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2267413 (or 2267410 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 27.

The square root of 20406663 is about 4517.3734625333. The cubic root of 20406663 is about 273.2691866458.

The spelling of 20406663 in words is "twenty million, four hundred six thousand, six hundred sixty-three".