11653721 has 4 divisors (see below), whose sum is σ = 12339252. Its totient is φ = 10968192.

The previous prime is 11653699. The next prime is 11653723. The reversal of 11653721 is 12735611.

11653721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5125696 + 6528025 = 2264^2 + 2555^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11653721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11653723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 342740 + ... + 342773.

It is an arithmetic number, because the mean of its divisors is an integer number (3084813).

Almost surely, 2^11653721 is an apocalyptic number.

It is an amenable number.

11653721 is a deficient number, since it is larger than the sum of its proper divisors (685531).

11653721 is an equidigital number, since it uses as much as digits as its factorization.

11653721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 685530.

The product of its digits is 1260, while the sum is 26.

The square root of 11653721 is about 3413.7546777705. The cubic root of 11653721 is about 226.7191504284.

The spelling of 11653721 in words is "eleven million, six hundred fifty-three thousand, seven hundred twenty-one".