11722721 has 2 divisors, whose sum is σ = 11722722. Its totient is φ = 11722720.

The previous prime is 11722717. The next prime is 11722723. The reversal of 11722721 is 12722711.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6948496 + 4774225 = 2636^2 + 2185^2 .

It is a cyclic number.

It is not a de Polignac number, because 11722721 - 2² = 11722717 is a prime.

Together with 11722723, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p₇₇₁₀₂₆ and since 11722721 and 771026 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (11722723) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5861360 + 5861361.

It is an arithmetic number, because the mean of its divisors is an integer number (5861361).

Almost surely, 2^11722721 is an apocalyptic number.

It is an amenable number.

11722721 is a deficient number, since it is larger than the sum of its proper divisors (1).

11722721 is an equidigital number, since it uses as much as digits as its factorization.

11722721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 392, while the sum is 23.

The square root of 11722721 is about 3423.8459369545. The cubic root of 11722721 is about 227.1657273342.

The spelling of 11722721 in words is "eleven million, seven hundred twenty-two thousand, seven hundred twenty-one".