11897661 has 4 divisors (see below), whose sum is σ = 15863552. Its totient is φ = 7931772.

The previous prime is 11897653. The next prime is 11897681. The reversal of 11897661 is 16679811.

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: 16679811 = 3 ⋅5559937.

It is not a de Polignac number, because 11897661 - 2³ = 11897653 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11897681) 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, 1982941 + ... + 1982946.

It is an arithmetic number, because the mean of its divisors is an integer number (3965888).

Almost surely, 2^11897661 is an apocalyptic number.

It is an amenable number.

11897661 is a deficient number, since it is larger than the sum of its proper divisors (3965891).

11897661 is an equidigital number, since it uses as much as digits as its factorization.

11897661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3965890.

The product of its digits is 18144, while the sum is 39.

The square root of 11897661 is about 3449.2986243583. The cubic root of 11897661 is about 228.2901622728.

It can be divided in two parts, 118 and 97661, that added together give a palindrome (97779).

The spelling of 11897661 in words is "eleven million, eight hundred ninety-seven thousand, six hundred sixty-one".