11707821 has 10 divisors (see below), whose sum is σ = 17489582. Its totient is φ = 7805160.

The previous prime is 11707811. The next prime is 11707823. The reversal of 11707821 is 12870711.

It can be written as a sum of positive squares in only one way, i.e., 11634921 + 72900 = 3411^2 + 270^2 .

It is not a de Polignac number, because 11707821 - 2⁵ = 11707789 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11707823) 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 9 ways as a sum of consecutive naturals, for example, 72190 + ... + 72351.

Almost surely, 2^11707821 is an apocalyptic number.

It is an amenable number.

11707821 is a deficient number, since it is larger than the sum of its proper divisors (5781761).

11707821 is an equidigital number, since it uses as much as digits as its factorization.

11707821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 144553 (or 144544 counting only the distinct ones).

The product of its (nonzero) digits is 784, while the sum is 27.

The square root of 11707821 is about 3421.6693294356. The cubic root of 11707821 is about 227.0694412585.

The spelling of 11707821 in words is "eleven million, seven hundred seven thousand, eight hundred twenty-one".