11681388 has 24 divisors (see below), whose sum is σ = 30285360. Its totient is φ = 3893760.

The previous prime is 11681353. The next prime is 11681399. The reversal of 11681388 is 88318611.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53973 + ... + 54188.

It is an arithmetic number, because the mean of its divisors is an integer number (1261890).

Almost surely, 2^11681388 is an apocalyptic number.

11681388 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

11681388 is an abundant number, since it is smaller than the sum of its proper divisors (18603972).

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

11681388 is a wasteful number, since it uses less digits than its factorization.

11681388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108174 (or 108166 counting only the distinct ones).

The product of its digits is 9216, while the sum is 36.

The square root of 11681388 is about 3417.8045584849. The cubic root of 11681388 is about 226.8984259671.

Adding to 11681388 its reverse (88318611), we get a palindrome (99999999).

It can be divided in two parts, 1168 and 1388, that added together give a triangular number (2556 = T₇₁).

The spelling of 11681388 in words is "eleven million, six hundred eighty-one thousand, three hundred eighty-eight".