11639988 has 18 divisors (see below), whose sum is σ = 29423394. Its totient is φ = 3879984.

The previous prime is 11639987. The next prime is 11640007. The reversal of 11639988 is 88993611.

11639988 is a `hidden beast` number, since 1 + 1 + 639 + 9 + 8 + 8 = 666.

11639988 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 7551504 + 4088484 = 2748^2 + 2022^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11639987) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 161631 + ... + 161702.

It is an arithmetic number, because the mean of its divisors is an integer number (1634633).

Almost surely, 2^11639988 is an apocalyptic number.

11639988 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

11639988 is an abundant number, since it is smaller than the sum of its proper divisors (17783406).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11639988 is a wasteful number, since it uses less digits than its factorization.

11639988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 323343 (or 323338 counting only the distinct ones).

The product of its digits is 93312, while the sum is 45.

The square root of 11639988 is about 3411.7426632148. The cubic root of 11639988 is about 226.6300584862.

It can be divided in two parts, 116 and 39988, that added together give a palindrome (40104).

The spelling of 11639988 in words is "eleven million, six hundred thirty-nine thousand, nine hundred eighty-eight".