11856305221 has 2 divisors, whose sum is σ = 11856305222. Its totient is φ = 11856305220.

The previous prime is 11856305207. The next prime is 11856305249. The reversal of 11856305221 is 12250365811.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11153472100 + 702833121 = 105610^2 + 26511^2 .

It is a cyclic number.

It is not a de Polignac number, because 11856305221 - 2¹⁵ = 11856272453 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11856305821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5928152610 + 5928152611.

It is an arithmetic number, because the mean of its divisors is an integer number (5928152611).

Almost surely, 2^11856305221 is an apocalyptic number.

It is an amenable number.

11856305221 is a deficient number, since it is larger than the sum of its proper divisors (1).

11856305221 is an equidigital number, since it uses as much as digits as its factorization.

11856305221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14400, while the sum is 34.

The spelling of 11856305221 in words is "eleven billion, eight hundred fifty-six million, three hundred five thousand, two hundred twenty-one".