20723145 has 16 divisors (see below), whose sum is σ = 34054080. Its totient is φ = 10753344.

The previous prime is 20723137. The next prime is 20723173. The reversal of 20723145 is 54132702.

It is not a de Polignac number, because 20723145 - 2³ = 20723137 is a prime.

It is a Curzon number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 18115 + ... + 19224.

It is an arithmetic number, because the mean of its divisors is an integer number (2128380).

Almost surely, 2^20723145 is an apocalyptic number.

It is an amenable number.

20723145 is a deficient number, since it is larger than the sum of its proper divisors (13330935).

20723145 is a wasteful number, since it uses less digits than its factorization.

20723145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37384.

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 20723145 is about 4552.2681160055. The cubic root of 20723145 is about 274.6746344802.

Adding to 20723145 its reverse (54132702), we get a palindrome (74855847).

The spelling of 20723145 in words is "twenty million, seven hundred twenty-three thousand, one hundred forty-five".