11155415221 has 2 divisors, whose sum is σ = 11155415222. Its totient is φ = 11155415220.

The previous prime is 11155415213. The next prime is 11155415251. The reversal of 11155415221 is 12251455111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9973018225 + 1182396996 = 99865^2 + 34386^2 .

It is a cyclic number.

It is not a de Polignac number, because 11155415221 - 2³ = 11155415213 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 11155415221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11155415251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5577707610 + 5577707611.

It is an arithmetic number, because the mean of its divisors is an integer number (5577707611).

Almost surely, 2^11155415221 is an apocalyptic number.

It is an amenable number.

11155415221 is a deficient number, since it is larger than the sum of its proper divisors (1).

11155415221 is an equidigital number, since it uses as much as digits as its factorization.

11155415221 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2000, while the sum is 28.

The spelling of 11155415221 in words is "eleven billion, one hundred fifty-five million, four hundred fifteen thousand, two hundred twenty-one".