221010406 has 4 divisors (see below), whose sum is σ = 331515612. Its totient is φ = 110505202.

The previous prime is 221010397. The next prime is 221010431. The reversal of 221010406 is 604010122.

It is a semiprime because it is the product of two primes.

It is a self number, because there is not a number n which added to its sum of digits gives 221010406.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55252600 + ... + 55252603.

It is an arithmetic number, because the mean of its divisors is an integer number (82878903).

Almost surely, 2^221010406 is an apocalyptic number.

221010406 is a deficient number, since it is larger than the sum of its proper divisors (110505206).

221010406 is a wasteful number, since it uses less digits than its factorization.

221010406 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110505205.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 221010406 is about 14866.4187348534. The cubic root of 221010406 is about 604.6038487569.

Adding to 221010406 its reverse (604010122), we get a palindrome (825020528).

The spelling of 221010406 in words is "two hundred twenty-one million, ten thousand, four hundred six".