221603401 has 4 divisors (see below), whose sum is σ = 227008404. Its totient is φ = 216198400.

The previous prime is 221603359. The next prime is 221603411. The reversal of 221603401 is 104306122.

221603401 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 can be written as a sum of positive squares in 2 ways, for example, as 7420176 + 214183225 = 2724^2 + 14635^2 .

It is a cyclic number.

It is not a de Polignac number, because 221603401 - 2⁷ = 221603273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221603411) 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, 2702440 + ... + 2702521.

It is an arithmetic number, because the mean of its divisors is an integer number (56752101).

Almost surely, 2^221603401 is an apocalyptic number.

It is an amenable number.

221603401 is a deficient number, since it is larger than the sum of its proper divisors (5405003).

221603401 is an equidigital number, since it uses as much as digits as its factorization.

221603401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5405002.

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 221603401 is about 14886.3494853507. The cubic root of 221603401 is about 605.1441051897.

Adding to 221603401 its reverse (104306122), we get a palindrome (325909523).

The spelling of 221603401 in words is "two hundred twenty-one million, six hundred three thousand, four hundred one".