11557921 has 4 divisors (see below), whose sum is σ = 11956500. Its totient is φ = 11159344.

The previous prime is 11557919. The next prime is 11557933. The reversal of 11557921 is 12975511.

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 3857296 + 7700625 = 1964^2 + 2775^2 .

It is a cyclic number.

It is not a de Polignac number, because 11557921 - 2¹ = 11557919 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11557951) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 199246 + ... + 199303.

It is an arithmetic number, because the mean of its divisors is an integer number (2989125).

Almost surely, 2^11557921 is an apocalyptic number.

It is an amenable number.

11557921 is a deficient number, since it is larger than the sum of its proper divisors (398579).

11557921 is an equidigital number, since it uses as much as digits as its factorization.

11557921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 398578.

The product of its digits is 3150, while the sum is 31.

The square root of 11557921 is about 3399.6942509585. The cubic root of 11557921 is about 226.0961882041.

It can be divided in two parts, 115579 and 21, that added together give a square (115600 = 340²).

The spelling of 11557921 in words is "eleven million, five hundred fifty-seven thousand, nine hundred twenty-one".