11691840 has 112 divisors (see below), whose sum is σ = 39136320. Its totient is φ = 2949120.

The previous prime is 11691793. The next prime is 11691851. The reversal of 11691840 is 4819611.

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

It is a junction number, because it is equal to n+sod(n) for n = 11691798 and 11691807.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17920 + ... + 18560.

Almost surely, 2^11691840 is an apocalyptic number.

11691840 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 11691840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19568160).

11691840 is an abundant number, since it is smaller than the sum of its proper divisors (27444480).

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

11691840 is a wasteful number, since it uses less digits than its factorization.

11691840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 680 (or 670 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 30.

The square root of 11691840 is about 3419.3332683434. Note that the first 3 decimals coincide. The cubic root of 11691840 is about 226.9660787547.

The spelling of 11691840 in words is "eleven million, six hundred ninety-one thousand, eight hundred forty".