11721397 has 2 divisors, whose sum is σ = 11721398. Its totient is φ = 11721396.

The previous prime is 11721373. The next prime is 11721407. The reversal of 11721397 is 79312711.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6380676 + 5340721 = 2526^2 + 2311^2 .

It is an emirp because it is prime and its reverse (79312711) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11721397 is a prime.

It is a super-2 number, since 2×11721397² = 274782295263218, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11721497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5860698 + 5860699.

It is an arithmetic number, because the mean of its divisors is an integer number (5860699).

Almost surely, 2^11721397 is an apocalyptic number.

It is an amenable number.

11721397 is a deficient number, since it is larger than the sum of its proper divisors (1).

11721397 is an equidigital number, since it uses as much as digits as its factorization.

11721397 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2646, while the sum is 31.

The square root of 11721397 is about 3423.6525816736. The cubic root of 11721397 is about 227.1571747479.

The spelling of 11721397 in words is "eleven million, seven hundred twenty-one thousand, three hundred ninety-seven".