11771561 has 8 divisors (see below), whose sum is σ = 12405120. Its totient is φ = 11148192.

The previous prime is 11771533. The next prime is 11771563. The reversal of 11771561 is 16517711.

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

It is a de Polignac number, because none of the positive numbers 2^k-11771561 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11771563) 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, 116 + ... + 4853.

It is an arithmetic number, because the mean of its divisors is an integer number (1550640).

Almost surely, 2^11771561 is an apocalyptic number.

It is an amenable number.

11771561 is a deficient number, since it is larger than the sum of its proper divisors (633559).

11771561 is a wasteful number, since it uses less digits than its factorization.

11771561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5095.

The product of its digits is 1470, while the sum is 29.

The square root of 11771561 is about 3430.9708538546. The cubic root of 11771561 is about 227.4807680075.

The spelling of 11771561 in words is "eleven million, seven hundred seventy-one thousand, five hundred sixty-one".