20101405 has 4 divisors (see below), whose sum is σ = 24121692. Its totient is φ = 16081120.

The previous prime is 20101399. The next prime is 20101421. The reversal of 20101405 is 50410102.

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 15952036 + 4149369 = 3994^2 + 2037^2 .

It is not a de Polignac number, because 20101405 - 2⁹ = 20100893 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 2010136 + ... + 2010145.

It is an arithmetic number, because the mean of its divisors is an integer number (6030423).

Almost surely, 2^20101405 is an apocalyptic number.

It is an amenable number.

20101405 is a deficient number, since it is larger than the sum of its proper divisors (4020287).

20101405 is an equidigital number, since it uses as much as digits as its factorization.

20101405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4020286.

The product of its (nonzero) digits is 40, while the sum is 13.

The square root of 20101405 is about 4483.4590440864. The cubic root of 20101405 is about 271.8997476922.

Adding to 20101405 its reverse (50410102), we get a palindrome (70511507).

The spelling of 20101405 in words is "twenty million, one hundred one thousand, four hundred five".