11729721 has 4 divisors (see below), whose sum is σ = 15639632. Its totient is φ = 7819812.

The previous prime is 11729719. The next prime is 11729723. The reversal of 11729721 is 12792711.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12792711 = 3 ⋅4264237.

It is an interprime number because it is at equal distance from previous prime (11729719) and next prime (11729723).

It is not a de Polignac number, because 11729721 - 2¹ = 11729719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11729723) 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, 1954951 + ... + 1954956.

It is an arithmetic number, because the mean of its divisors is an integer number (3909908).

Almost surely, 2^11729721 is an apocalyptic number.

It is an amenable number.

11729721 is a deficient number, since it is larger than the sum of its proper divisors (3909911).

11729721 is an equidigital number, since it uses as much as digits as its factorization.

11729721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3909910.

The product of its digits is 1764, while the sum is 30.

The square root of 11729721 is about 3424.8680266545. The cubic root of 11729721 is about 227.2109342358.

The spelling of 11729721 in words is "eleven million, seven hundred twenty-nine thousand, seven hundred twenty-one".