20101801 has 4 divisors (see below), whose sum is σ = 20120004. Its totient is φ = 20083600.

The previous prime is 20101771. The next prime is 20101817. The reversal of 20101801 is 10810102.

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 19053225 + 1048576 = 4365^2 + 1024^2 .

It is a cyclic number.

It is not a de Polignac number, because 20101801 - 2⁷ = 20101673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20101001) 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, 7330 + ... + 9691.

It is an arithmetic number, because the mean of its divisors is an integer number (5030001).

Almost surely, 2^20101801 is an apocalyptic number.

It is an amenable number.

20101801 is a deficient number, since it is larger than the sum of its proper divisors (18203).

20101801 is a wasteful number, since it uses less digits than its factorization.

20101801 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18202.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 20101801 is about 4483.5032061994. The cubic root of 20101801 is about 271.9015331660.

Adding to 20101801 its reverse (10810102), we get a palindrome (30911903).

It can be divided in two parts, 20101 and 801, that added together give a palindrome (20902).

The spelling of 20101801 in words is "twenty million, one hundred one thousand, eight hundred one".