11813621 has 2 divisors, whose sum is σ = 11813622. Its totient is φ = 11813620.

The previous prime is 11813609. The next prime is 11813653. The reversal of 11813621 is 12631811.

11813621 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10491121 + 1322500 = 3239^2 + 1150^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11813621 is a prime.

It is a super-2 number, since 2×11813621² = 279123282263282, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11812621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5906810 + 5906811.

It is an arithmetic number, because the mean of its divisors is an integer number (5906811).

Almost surely, 2^11813621 is an apocalyptic number.

It is an amenable number.

11813621 is a deficient number, since it is larger than the sum of its proper divisors (1).

11813621 is an equidigital number, since it uses as much as digits as its factorization.

11813621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 288, while the sum is 23.

The square root of 11813621 is about 3437.0948488513. The cubic root of 11813621 is about 227.7513769300.

The spelling of 11813621 in words is "eleven million, eight hundred thirteen thousand, six hundred twenty-one".