221221312401 has 16 divisors (see below), whose sum is σ = 299108703296. Its totient is φ = 145408836096.

The previous prime is 221221312357. The next prime is 221221312421. The reversal of 221221312401 is 104213122122.

It is a happy number.

It is not a de Polignac number, because 221221312401 - 2⁶ = 221221312337 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221221312421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 442146 + ... + 798708.

It is an arithmetic number, because the mean of its divisors is an integer number (18694293956).

Almost surely, 2^221221312401 is an apocalyptic number.

It is an amenable number.

221221312401 is a deficient number, since it is larger than the sum of its proper divisors (77887390895).

221221312401 is a wasteful number, since it uses less digits than its factorization.

221221312401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359472.

The product of its (nonzero) digits is 384, while the sum is 21.

Adding to 221221312401 its reverse (104213122122), we get a palindrome (325434434523).

The spelling of 221221312401 in words is "two hundred twenty-one billion, two hundred twenty-one million, three hundred twelve thousand, four hundred one".