11999520 has 144 divisors (see below), whose sum is σ = 44167032. Its totient is φ = 2949120.

The previous prime is 11999513. The next prime is 11999527. The reversal of 11999520 is 2599911.

It is an interprime number because it is at equal distance from previous prime (11999513) and next prime (11999527).

It can be written as a sum of positive squares in 4 ways, for example, as 9960336 + 2039184 = 3156^2 + 1428^2 .

It is a tau number, because it is divible by the number of its divisors (144).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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

It is not an unprimeable number, because it can be changed into a prime (11999527) 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, 18400 + ... + 19040.

Almost surely, 2^11999520 is an apocalyptic number.

11999520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 11999520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22083516).

11999520 is an abundant number, since it is smaller than the sum of its proper divisors (32167512).

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

11999520 is a wasteful number, since it uses less digits than its factorization.

11999520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 675 (or 664 counting only the distinct ones).

The product of its (nonzero) digits is 7290, while the sum is 36.

The square root of 11999520 is about 3464.0323324126. The cubic root of 11999520 is about 228.9397958987.

The spelling of 11999520 in words is "eleven million, nine hundred ninety-nine thousand, five hundred twenty".