20145765 has 32 divisors (see below), whose sum is σ = 34387200. Its totient is φ = 10036224.

The previous prime is 20145743. The next prime is 20145767. The reversal of 20145765 is 56754102.

It is not a de Polignac number, because 20145765 - 2⁶ = 20145701 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20145767) 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 31 ways as a sum of consecutive naturals, for example, 50547 + ... + 50943.

It is an arithmetic number, because the mean of its divisors is an integer number (1074600).

Almost surely, 2^20145765 is an apocalyptic number.

It is an amenable number.

20145765 is a deficient number, since it is larger than the sum of its proper divisors (14241435).

20145765 is a wasteful number, since it uses less digits than its factorization.

20145765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 621.

The product of its (nonzero) digits is 8400, while the sum is 30.

The square root of 20145765 is about 4488.4033909621. The cubic root of 20145765 is about 272.0996111877.

Adding to 20145765 its reverse (56754102), we get a palindrome (76899867).

It can be divided in two parts, 20145 and 765, that added together give a triangular number (20910 = T₂₀₄).

The spelling of 20145765 in words is "twenty million, one hundred forty-five thousand, seven hundred sixty-five".