11989989 has 24 divisors (see below), whose sum is σ = 19004544. Its totient is φ = 7224000.

The previous prime is 11989987. The next prime is 11989993. The reversal of 11989989 is 98998911.

It is not a de Polignac number, because 11989989 - 2¹ = 11989987 is a prime.

Its product of digits (419904) is a multiple of the sum of its prime factors (729).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11989987) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27604 + ... + 28034.

It is an arithmetic number, because the mean of its divisors is an integer number (791856).

Almost surely, 2^11989989 is an apocalyptic number.

It is an amenable number.

11989989 is a deficient number, since it is larger than the sum of its proper divisors (7014555).

11989989 is a wasteful number, since it uses less digits than its factorization.

11989989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 729 (or 726 counting only the distinct ones).

The product of its digits is 419904, while the sum is 54.

The square root of 11989989 is about 3462.6563502606. The cubic root of 11989989 is about 228.8791656078.

The spelling of 11989989 in words is "eleven million, nine hundred eighty-nine thousand, nine hundred eighty-nine".