11920721 has 2 divisors, whose sum is σ = 11920722. Its totient is φ = 11920720.

The previous prime is 11920703. The next prime is 11920747. The reversal of 11920721 is 12702911.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11730625 + 190096 = 3425^2 + 436^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11920721 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (11929721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5960360 + 5960361.

It is an arithmetic number, because the mean of its divisors is an integer number (5960361).

Almost surely, 2^11920721 is an apocalyptic number.

It is an amenable number.

11920721 is a deficient number, since it is larger than the sum of its proper divisors (1).

11920721 is an equidigital number, since it uses as much as digits as its factorization.

11920721 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 252, while the sum is 23.

The square root of 11920721 is about 3452.6397147690. The cubic root of 11920721 is about 228.4375574533.

The spelling of 11920721 in words is "eleven million, nine hundred twenty thousand, seven hundred twenty-one".