11991630 has 64 divisors (see below), whose sum is σ = 34836480. Its totient is φ = 2578944.

The previous prime is 11991619. The next prime is 11991631. The reversal of 11991630 is 3619911.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11991631) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1891 + ... + 5249.

It is an arithmetic number, because the mean of its divisors is an integer number (544320).

Almost surely, 2^11991630 is an apocalyptic number.

11991630 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 11991630, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17418240).

11991630 is an abundant number, since it is smaller than the sum of its proper divisors (22844850).

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

11991630 is a wasteful number, since it uses less digits than its factorization.

11991630 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3393.

The product of its (nonzero) digits is 1458, while the sum is 30.

The square root of 11991630 is about 3462.8932989626. The cubic root of 11991630 is about 228.8896069178.

It can be divided in two parts, 11991 and 630, that added together give a palindrome (12621).

The spelling of 11991630 in words is "eleven million, nine hundred ninety-one thousand, six hundred thirty".