11991730 has 32 divisors (see below), whose sum is σ = 22560768. Its totient is φ = 4584000.

The previous prime is 11991719. The next prime is 11991731. The reversal of 11991730 is 3719911.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a junction number, because it is equal to n+sod(n) for n = 11991692 and 11991701.

It is not an unprimeable number, because it can be changed into a prime (11991731) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31119 + ... + 31501.

It is an arithmetic number, because the mean of its divisors is an integer number (705024).

Almost surely, 2^11991730 is an apocalyptic number.

11991730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

11991730 is a deficient number, since it is larger than the sum of its proper divisors (10569038).

11991730 is a wasteful number, since it uses less digits than its factorization.

11991730 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 522.

The product of its (nonzero) digits is 1701, while the sum is 31.

The square root of 11991730 is about 3462.9077377256. The cubic root of 11991730 is about 228.8902431643.

It can be divided in two parts, 11991 and 730, that added together give a palindrome (12721).

The spelling of 11991730 in words is "eleven million, nine hundred ninety-one thousand, seven hundred thirty".