20669145 has 32 divisors (see below), whose sum is σ = 38188800. Its totient is φ = 9350400.

The previous prime is 20669137. The next prime is 20669149. The reversal of 20669145 is 54196602.

It is not a de Polignac number, because 20669145 - 2³ = 20669137 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20669149) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9631 + ... + 11579.

It is an arithmetic number, because the mean of its divisors is an integer number (1193400).

Almost surely, 2^20669145 is an apocalyptic number.

It is an amenable number.

20669145 is a deficient number, since it is larger than the sum of its proper divisors (17519655).

20669145 is a wasteful number, since it uses less digits than its factorization.

20669145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2065.

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 20669145 is about 4546.3331378156. Note that the first 3 decimals coincide. The cubic root of 20669145 is about 274.4358462026.

It can be divided in two parts, 2066 and 9145, that added together give a palindrome (11211).

The spelling of 20669145 in words is "twenty million, six hundred sixty-nine thousand, one hundred forty-five".