221153987 has 2 divisors, whose sum is σ = 221153988. Its totient is φ = 221153986.

The previous prime is 221153981. The next prime is 221154019. The reversal of 221153987 is 789351122.

221153987 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221153987 - 2¹⁰ = 221152963 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 221153987.

It is not a weakly prime, because it can be changed into another prime (221153981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110576993 + 110576994.

It is an arithmetic number, because the mean of its divisors is an integer number (110576994).

Almost surely, 2^221153987 is an apocalyptic number.

221153987 is a deficient number, since it is larger than the sum of its proper divisors (1).

221153987 is an equidigital number, since it uses as much as digits as its factorization.

221153987 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30240, while the sum is 38.

The square root of 221153987 is about 14871.2469887364. The cubic root of 221153987 is about 604.7347488273.

The spelling of 221153987 in words is "two hundred twenty-one million, one hundred fifty-three thousand, nine hundred eighty-seven".