20511345 has 8 divisors (see below), whose sum is σ = 32818176. Its totient is φ = 10939376.

The previous prime is 20511341. The next prime is 20511347. The reversal of 20511345 is 54311502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20511345 - 2² = 20511341 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20511341) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 683697 + ... + 683726.

It is an arithmetic number, because the mean of its divisors is an integer number (4102272).

Almost surely, 2^20511345 is an apocalyptic number.

It is an amenable number.

20511345 is a deficient number, since it is larger than the sum of its proper divisors (12306831).

20511345 is a wasteful number, since it uses less digits than its factorization.

20511345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1367431.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 20511345 is about 4528.9452414442. The cubic root of 20511345 is about 273.7356615580.

Adding to 20511345 its reverse (54311502), we get a palindrome (74822847).

The spelling of 20511345 in words is "twenty million, five hundred eleven thousand, three hundred forty-five".