11947561 has 4 divisors (see below), whose sum is σ = 12576400. Its totient is φ = 11318724.

The previous prime is 11947547. The next prime is 11947567. The reversal of 11947561 is 16574911.

11947561 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, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 16574911 = 79 ⋅209809.

It is a cyclic number.

It is not a de Polignac number, because 11947561 - 2⁷ = 11947433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11947567) 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, 314391 + ... + 314428.

It is an arithmetic number, because the mean of its divisors is an integer number (3144100).

Almost surely, 2^11947561 is an apocalyptic number.

It is an amenable number.

11947561 is a deficient number, since it is larger than the sum of its proper divisors (628839).

11947561 is an equidigital number, since it uses as much as digits as its factorization.

11947561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 628838.

The product of its digits is 7560, while the sum is 34.

The square root of 11947561 is about 3456.5244104447. The cubic root of 11947561 is about 228.6088745012.

The spelling of 11947561 in words is "eleven million, nine hundred forty-seven thousand, five hundred sixty-one".