20513235 has 16 divisors (see below), whose sum is σ = 32946336. Its totient is φ = 10898688.

The previous prime is 20513231. The next prime is 20513257. The reversal of 20513235 is 53231502.

It is not a de Polignac number, because 20513235 - 2² = 20513231 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20513231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1687 + ... + 6623.

It is an arithmetic number, because the mean of its divisors is an integer number (2059146).

Almost surely, 2^20513235 is an apocalyptic number.

20513235 is a deficient number, since it is larger than the sum of its proper divisors (12433101).

20513235 is a wasteful number, since it uses less digits than its factorization.

20513235 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5222.

The product of its (nonzero) digits is 900, while the sum is 21.

The square root of 20513235 is about 4529.1538944929. The cubic root of 20513235 is about 273.7440690110.

Adding to 20513235 its reverse (53231502), we get a palindrome (73744737).

The spelling of 20513235 in words is "twenty million, five hundred thirteen thousand, two hundred thirty-five".