221290555 has 8 divisors (see below), whose sum is σ = 274114944. Its totient is φ = 171321600.

The previous prime is 221290543. The next prime is 221290583. The reversal of 221290555 is 555092122.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-221290555 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 713686 + ... + 713995.

It is an arithmetic number, because the mean of its divisors is an integer number (34264368).

Almost surely, 2^221290555 is an apocalyptic number.

221290555 is a deficient number, since it is larger than the sum of its proper divisors (52824389).

221290555 is a wasteful number, since it uses less digits than its factorization.

221290555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1427717.

The product of its (nonzero) digits is 9000, while the sum is 31.

The square root of 221290555 is about 14875.8379595907. The cubic root of 221290555 is about 604.8592027161.

The spelling of 221290555 in words is "two hundred twenty-one million, two hundred ninety thousand, five hundred fifty-five".