221210401 has 4 divisors (see below), whose sum is σ = 221254192. Its totient is φ = 221166612.

The previous prime is 221210387. The next prime is 221210413. The reversal of 221210401 is 104012122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221210401 - 2¹⁹ = 220686113 is a prime.

It is a super-3 number, since 3×221210401³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221210471) 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, 13155 + ... + 24808.

It is an arithmetic number, because the mean of its divisors is an integer number (55313548).

Almost surely, 2^221210401 is an apocalyptic number.

It is an amenable number.

221210401 is a deficient number, since it is larger than the sum of its proper divisors (43791).

221210401 is an equidigital number, since it uses as much as digits as its factorization.

221210401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43790.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 221210401 is about 14873.1436152550. The cubic root of 221210401 is about 604.7861648959.

Adding to 221210401 its reverse (104012122), we get a palindrome (325222523).

The spelling of 221210401 in words is "two hundred twenty-one million, two hundred ten thousand, four hundred one".