11987920 has 40 divisors (see below), whose sum is σ = 31855104. Its totient is φ = 4109952.

The previous prime is 11987909. The next prime is 11987923. The reversal of 11987920 is 2978911.

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 11987920.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11987923) 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, 10144 + ... + 11263.

Almost surely, 2^11987920 is an apocalyptic number.

11987920 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

11987920 is an abundant number, since it is smaller than the sum of its proper divisors (19867184).

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

11987920 is a wasteful number, since it uses less digits than its factorization.

11987920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21427 (or 21421 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 37.

The square root of 11987920 is about 3462.3575782983. The cubic root of 11987920 is about 228.8659996731.

Subtracting from 11987920 its reverse (2978911), we obtain a palindrome (9009009).

The spelling of 11987920 in words is "eleven million, nine hundred eighty-seven thousand, nine hundred twenty".