221255405 has 16 divisors (see below), whose sum is σ = 303832704. Its totient is φ = 151519680.

The previous prime is 221255389. The next prime is 221255407. The reversal of 221255405 is 504552122.

221255405 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 221255405 - 2⁴ = 221255389 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221255407) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 26150 + ... + 33560.

It is an arithmetic number, because the mean of its divisors is an integer number (18989544).

Almost surely, 2^221255405 is an apocalyptic number.

It is an amenable number.

221255405 is a deficient number, since it is larger than the sum of its proper divisors (82577299).

221255405 is an equidigital number, since it uses as much as digits as its factorization.

221255405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8276.

The product of its (nonzero) digits is 4000, while the sum is 26.

The square root of 221255405 is about 14874.6564666213. The cubic root of 221255405 is about 604.8271755520.

The spelling of 221255405 in words is "two hundred twenty-one million, two hundred fifty-five thousand, four hundred five".