11787821 has 8 divisors (see below), whose sum is σ = 12063480. Its totient is φ = 11515392.

The previous prime is 11787767. The next prime is 11787857. The reversal of 11787821 is 12878711.

It can be written as a sum of positive squares in 4 ways, for example, as 302500 + 11485321 = 550^2 + 3389^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 11787821 - 2²² = 7593517 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 (11787121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7535 + ... + 8963.

It is an arithmetic number, because the mean of its divisors is an integer number (1507935).

Almost surely, 2^11787821 is an apocalyptic number.

It is an amenable number.

11787821 is a deficient number, since it is larger than the sum of its proper divisors (275659).

11787821 is a wasteful number, since it uses less digits than its factorization.

11787821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1615.

The product of its digits is 6272, while the sum is 35.

The square root of 11787821 is about 3433.3396278259. The cubic root of 11787821 is about 227.5854591790.

The spelling of 11787821 in words is "eleven million, seven hundred eighty-seven thousand, eight hundred twenty-one".