11507721 has 4 divisors (see below), whose sum is σ = 15343632. Its totient is φ = 7671812.

The previous prime is 11507707. The next prime is 11507723. The reversal of 11507721 is 12770511.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11507721 is a prime.

It is a super-2 number, since 2×11507721² = 264855285227682, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 11507691 and 11507700.

It is not an unprimeable number, because it can be changed into a prime (11507723) 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 3 ways as a sum of consecutive naturals, for example, 1917951 + ... + 1917956.

It is an arithmetic number, because the mean of its divisors is an integer number (3835908).

Almost surely, 2^11507721 is an apocalyptic number.

It is an amenable number.

11507721 is a deficient number, since it is larger than the sum of its proper divisors (3835911).

11507721 is an equidigital number, since it uses as much as digits as its factorization.

11507721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3835910.

The product of its (nonzero) digits is 490, while the sum is 24.

The square root of 11507721 is about 3392.3031998924. The cubic root of 11507721 is about 225.7683754783.

The spelling of 11507721 in words is "eleven million, five hundred seven thousand, seven hundred twenty-one".