20109497 has 4 divisors (see below), whose sum is σ = 20128740. Its totient is φ = 20090256.

The previous prime is 20109493. The next prime is 20109503. The reversal of 20109497 is 79490102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3225616 + 16883881 = 1796^2 + 4109^2 .

It is a cyclic number.

It is not a de Polignac number, because 20109497 - 2² = 20109493 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20109491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7958 + ... + 10175.

It is an arithmetic number, because the mean of its divisors is an integer number (5032185).

Almost surely, 2^20109497 is an apocalyptic number.

It is an amenable number.

20109497 is a deficient number, since it is larger than the sum of its proper divisors (19243).

20109497 is a wasteful number, since it uses less digits than its factorization.

20109497 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19242.

The product of its (nonzero) digits is 4536, while the sum is 32.

The square root of 20109497 is about 4484.3613815124. The cubic root of 20109497 is about 271.9362280209.

Adding to 20109497 its reverse (79490102), we get a palindrome (99599599).

The spelling of 20109497 in words is "twenty million, one hundred nine thousand, four hundred ninety-seven".