11772821 has 4 divisors (see below), whose sum is σ = 11858892. Its totient is φ = 11686752.

The previous prime is 11772809. The next prime is 11772833. The reversal of 11772821 is 12827711.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (11772809) and next prime (11772833).

It can be written as a sum of positive squares in 2 ways, for example, as 7214596 + 4558225 = 2686^2 + 2135^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11772821 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11772121) 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, 42830 + ... + 43103.

It is an arithmetic number, because the mean of its divisors is an integer number (2964723).

Almost surely, 2^11772821 is an apocalyptic number.

It is an amenable number.

11772821 is a deficient number, since it is larger than the sum of its proper divisors (86071).

11772821 is an equidigital number, since it uses as much as digits as its factorization.

11772821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86070.

The product of its digits is 1568, while the sum is 29.

The square root of 11772821 is about 3431.1544704370. The cubic root of 11772821 is about 227.4888840521.

The spelling of 11772821 in words is "eleven million, seven hundred seventy-two thousand, eight hundred twenty-one".