20109895 has 16 divisors (see below), whose sum is σ = 27518400. Its totient is φ = 13976064.

The previous prime is 20109893. The next prime is 20109911. The reversal of 20109895 is 59890102.

It is a cyclic number.

It is not a de Polignac number, because 20109895 - 2¹ = 20109893 is a prime.

It is a super-2 number, since 2×20109895² = 808815753822050, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20109895.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20109893) 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 15 ways as a sum of consecutive naturals, for example, 7995 + ... + 10204.

It is an arithmetic number, because the mean of its divisors is an integer number (1719900).

Almost surely, 2^20109895 is an apocalyptic number.

20109895 is a deficient number, since it is larger than the sum of its proper divisors (7408505).

20109895 is a wasteful number, since it uses less digits than its factorization.

20109895 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18234.

The product of its (nonzero) digits is 6480, while the sum is 34.

The square root of 20109895 is about 4484.4057577342. The cubic root of 20109895 is about 271.9380220307.

Adding to 20109895 its reverse (59890102), we get a palindrome (79999997).

The spelling of 20109895 in words is "twenty million, one hundred nine thousand, eight hundred ninety-five".