221366051 has 4 divisors (see below), whose sum is σ = 223853400. Its totient is φ = 218878704.

The previous prime is 221366039. The next prime is 221366059. The reversal of 221366051 is 150663122.

221366051 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 221366051 - 2¹⁸ = 221103907 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221366051.

It is not an unprimeable number, because it can be changed into a prime (221366059) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1243541 + ... + 1243718.

It is an arithmetic number, because the mean of its divisors is an integer number (55963350).

Almost surely, 2^221366051 is an apocalyptic number.

221366051 is a deficient number, since it is larger than the sum of its proper divisors (2487349).

221366051 is an equidigital number, since it uses as much as digits as its factorization.

221366051 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2487348.

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 221366051 is about 14878.3752809237. The cubic root of 221366051 is about 604.9279799523.

The spelling of 221366051 in words is "two hundred twenty-one million, three hundred sixty-six thousand, fifty-one".