20345505 has 16 divisors (see below), whose sum is σ = 32700480. Its totient is φ = 10801728.

The previous prime is 20345491. The next prime is 20345509. The reversal of 20345505 is 50554302.

It is not a de Polignac number, because 20345505 - 2⁶ = 20345441 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20345509) 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, 474 + ... + 6396.

It is an arithmetic number, because the mean of its divisors is an integer number (2043780).

Almost surely, 2^20345505 is an apocalyptic number.

It is an amenable number.

20345505 is a deficient number, since it is larger than the sum of its proper divisors (12354975).

20345505 is a wasteful number, since it uses less digits than its factorization.

20345505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6160.

The product of its (nonzero) digits is 3000, while the sum is 24.

The square root of 20345505 is about 4510.5991841439. The cubic root of 20345505 is about 272.9959209899.

Adding to 20345505 its reverse (50554302), we get a palindrome (70899807).

The spelling of 20345505 in words is "twenty million, three hundred forty-five thousand, five hundred five".