11721505 has 4 divisors (see below), whose sum is σ = 14065812. Its totient is φ = 9377200.

The previous prime is 11721497. The next prime is 11721511. The reversal of 11721505 is 50512711.

11721505 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 8567329 + 3154176 = 2927^2 + 1776^2 .

It is not a de Polignac number, because 11721505 - 2³ = 11721497 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1172146 + ... + 1172155.

It is an arithmetic number, because the mean of its divisors is an integer number (3516453).

Almost surely, 2^11721505 is an apocalyptic number.

It is an amenable number.

11721505 is a deficient number, since it is larger than the sum of its proper divisors (2344307).

11721505 is an equidigital number, since it uses as much as digits as its factorization.

11721505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2344306.

The product of its (nonzero) digits is 350, while the sum is 22.

The square root of 11721505 is about 3423.6683542656. The cubic root of 11721505 is about 227.1578724151.

The spelling of 11721505 in words is "eleven million, seven hundred twenty-one thousand, five hundred five".