11388981 has 8 divisors (see below), whose sum is σ = 15212320. Its totient is φ = 7579152.

The previous prime is 11388959. The next prime is 11388983. The reversal of 11388981 is 18988311.

11388981 is digitally balanced in base 2, base 3 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 11388981 - 2²¹ = 9291829 is a prime.

It is a super-2 number, since 2×11388981² = 259417776436722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11388983) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1210 + ... + 4923.

It is an arithmetic number, because the mean of its divisors is an integer number (1901540).

Almost surely, 2^11388981 is an apocalyptic number.

It is an amenable number.

11388981 is a deficient number, since it is larger than the sum of its proper divisors (3823339).

11388981 is an equidigital number, since it uses as much as digits as its factorization.

11388981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6755.

The product of its digits is 13824, while the sum is 39.

The square root of 11388981 is about 3374.7564356558. The cubic root of 11388981 is about 224.9891747878.

The spelling of 11388981 in words is "eleven million, three hundred eighty-eight thousand, nine hundred eighty-one".