20117545 has 16 divisors (see below), whose sum is σ = 29213568. Its totient is φ = 12983040.

The previous prime is 20117527. The next prime is 20117549. The reversal of 20117545 is 54571102.

It is not a de Polignac number, because 20117545 - 2¹⁹ = 19593257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20117549) 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, 16311 + ... + 17500.

It is an arithmetic number, because the mean of its divisors is an integer number (1825848).

Almost surely, 2^20117545 is an apocalyptic number.

It is an amenable number.

20117545 is a deficient number, since it is larger than the sum of its proper divisors (9096023).

20117545 is a wasteful number, since it uses less digits than its factorization.

20117545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33840.

The product of its (nonzero) digits is 1400, while the sum is 25.

The square root of 20117545 is about 4485.2586324537. The cubic root of 20117545 is about 271.9725002835.

Adding to 20117545 its reverse (54571102), we get a palindrome (74688647).

The spelling of 20117545 in words is "twenty million, one hundred seventeen thousand, five hundred forty-five".