11501721 has 36 divisors (see below), whose sum is σ = 21091824. Its totient is φ = 5972400.

The previous prime is 11501717. The next prime is 11501723. The reversal of 11501721 is 12710511.

It is a happy number.

It is not a de Polignac number, because 11501721 - 2² = 11501717 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11501694 and 11501703.

It is not an unprimeable number, because it can be changed into a prime (11501723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 3666 + ... + 6036.

It is an arithmetic number, because the mean of its divisors is an integer number (585884).

Almost surely, 2^11501721 is an apocalyptic number.

11501721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

11501721 is a deficient number, since it is larger than the sum of its proper divisors (9590103).

11501721 is a wasteful number, since it uses less digits than its factorization.

11501721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2402 (or 2392 counting only the distinct ones).

The product of its (nonzero) digits is 70, while the sum is 18.

The square root of 11501721 is about 3391.4187296764. The cubic root of 11501721 is about 225.7291309355.

The spelling of 11501721 in words is "eleven million, five hundred one thousand, seven hundred twenty-one".