221368405 has 8 divisors (see below), whose sum is σ = 267127200. Its totient is φ = 176104656.

The previous prime is 221368393. The next prime is 221368417. The reversal of 221368405 is 504863122.

It is an interprime number because it is at equal distance from previous prime (221368393) and next prime (221368417).

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 221368405 - 2¹⁵ = 221335637 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 122775 + ... + 124564.

It is an arithmetic number, because the mean of its divisors is an integer number (33390900).

Almost surely, 2^221368405 is an apocalyptic number.

It is an amenable number.

221368405 is a deficient number, since it is larger than the sum of its proper divisors (45758795).

221368405 is a wasteful number, since it uses less digits than its factorization.

221368405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247523.

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 221368405 is about 14878.4543888134. The cubic root of 221368405 is about 604.9301242068.

The spelling of 221368405 in words is "two hundred twenty-one million, three hundred sixty-eight thousand, four hundred five".