11989618 has 4 divisors (see below), whose sum is σ = 17984430. Its totient is φ = 5994808.

The previous prime is 11989597. The next prime is 11989657. The reversal of 11989618 is 81698911.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81698911 = 7 ⋅11671273.

It can be written as a sum of positive squares in only one way, i.e., 6985449 + 5004169 = 2643^2 + 2237^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2997403 + ... + 2997406.

Almost surely, 2^11989618 is an apocalyptic number.

11989618 is a deficient number, since it is larger than the sum of its proper divisors (5994812).

11989618 is an equidigital number, since it uses as much as digits as its factorization.

11989618 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5994811.

The product of its digits is 31104, while the sum is 43.

The square root of 11989618 is about 3462.6027782580. The cubic root of 11989618 is about 228.8768048871.

It can be divided in two parts, 1198 and 9618, that added together give a square (10816 = 104²).

The spelling of 11989618 in words is "eleven million, nine hundred eighty-nine thousand, six hundred eighteen".