20618091 has 16 divisors (see below), whose sum is σ = 32895520. Its totient is φ = 12687840.

The previous prime is 20618083. The next prime is 20618107. The reversal of 20618091 is 19081602.

It is not a de Polignac number, because 20618091 - 2³ = 20618083 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20618011) 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, 29020 + ... + 29721.

It is an arithmetic number, because the mean of its divisors is an integer number (2055970).

Almost surely, 2^20618091 is an apocalyptic number.

20618091 is a deficient number, since it is larger than the sum of its proper divisors (12277429).

20618091 is a wasteful number, since it uses less digits than its factorization.

20618091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 58763 (or 58757 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 27.

The square root of 20618091 is about 4540.7148115688. The cubic root of 20618091 is about 274.2097023606.

Adding to 20618091 its reverse (19081602), we get a palindrome (39699693).

The spelling of 20618091 in words is "twenty million, six hundred eighteen thousand, ninety-one".