221390105 has 8 divisors (see below), whose sum is σ = 265805064. Its totient is φ = 177020800.

The previous prime is 221390077. The next prime is 221390123. The reversal of 221390105 is 501093122.

It can be written as a sum of positive squares in 4 ways, for example, as 28430224 + 192959881 = 5332^2 + 13891^2 .

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

It is not a de Polignac number, because 221390105 - 2¹⁸ = 221127961 is a prime.

It is a super-2 number, since 2×221390105² = 98027157183822050, which contains 22 as substring.

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, 365 + ... + 21045.

It is an arithmetic number, because the mean of its divisors is an integer number (33225633).

Almost surely, 2^221390105 is an apocalyptic number.

It is an amenable number.

221390105 is a deficient number, since it is larger than the sum of its proper divisors (44414959).

221390105 is a wasteful number, since it uses less digits than its factorization.

221390105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22827.

The product of its (nonzero) digits is 540, while the sum is 23.

The square root of 221390105 is about 14879.1836133573. The cubic root of 221390105 is about 604.9498899826.

The spelling of 221390105 in words is "two hundred twenty-one million, three hundred ninety thousand, one hundred five".