20615145 has 16 divisors (see below), whose sum is σ = 33607872. Its totient is φ = 10786880.

The previous prime is 20615117. The next prime is 20615149. The reversal of 20615145 is 54151602.

It is not a de Polignac number, because 20615145 - 2⁵ = 20615113 is a prime.

It is a super-3 number, since 3×20615145³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (20615149) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12171 + ... + 13760.

It is an arithmetic number, because the mean of its divisors is an integer number (2100492).

Almost surely, 2^20615145 is an apocalyptic number.

It is an amenable number.

20615145 is a deficient number, since it is larger than the sum of its proper divisors (12992727).

20615145 is a wasteful number, since it uses less digits than its factorization.

20615145 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25992.

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 20615145 is about 4540.3904017166. The cubic root of 20615145 is about 274.1966416580.

Adding to 20615145 its reverse (54151602), we get a palindrome (74766747).

It can be divided in two parts, 206 and 15145, that added together give a palindrome (15351).

The spelling of 20615145 in words is "twenty million, six hundred fifteen thousand, one hundred forty-five".