20807145 has 16 divisors (see below), whose sum is σ = 36990720. Its totient is φ = 11097072.

The previous prime is 20807093. The next prime is 20807153. The reversal of 20807145 is 54170802.

It is not a de Polignac number, because 20807145 - 2⁶ = 20807081 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76929 + ... + 77198.

It is an arithmetic number, because the mean of its divisors is an integer number (2311920).

Almost surely, 2^20807145 is an apocalyptic number.

It is an amenable number.

20807145 is a deficient number, since it is larger than the sum of its proper divisors (16183575).

20807145 is a wasteful number, since it uses less digits than its factorization.

20807145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154141 (or 154135 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 27.

The square root of 20807145 is about 4561.4849555819. The cubic root of 20807145 is about 275.0452597683.

Adding to 20807145 its reverse (54170802), we get a palindrome (74977947).

The spelling of 20807145 in words is "twenty million, eight hundred seven thousand, one hundred forty-five".