405555221 has 8 divisors (see below), whose sum is σ = 411977184. Its totient is φ = 399144240.

The previous prime is 405555211. The next prime is 405555229. The reversal of 405555221 is 122555504.

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

It is a cyclic number.

It is not a de Polignac number, because 405555221 - 2¹⁰ = 405554197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405555229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 103331 + ... + 107183.

It is an arithmetic number, because the mean of its divisors is an integer number (51497148).

Almost surely, 2^405555221 is an apocalyptic number.

It is an amenable number.

405555221 is a deficient number, since it is larger than the sum of its proper divisors (6421963).

405555221 is a wasteful number, since it uses less digits than its factorization.

405555221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5491.

The product of its (nonzero) digits is 10000, while the sum is 29.

The square root of 405555221 is about 20138.4016495848. The cubic root of 405555221 is about 740.2015648872.

The spelling of 405555221 in words is "four hundred five million, five hundred fifty-five thousand, two hundred twenty-one".