221432401 has 4 divisors (see below), whose sum is σ = 221601600. Its totient is φ = 221263204.

The previous prime is 221432399. The next prime is 221432417. The reversal of 221432401 is 104234122.

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, and also an emirpimes, since its reverse is a distinct semiprime: 104234122 = 2 ⋅52117061.

It is a cyclic number.

It is not a de Polignac number, because 221432401 - 2¹ = 221432399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221438401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82621 + ... + 85258.

It is an arithmetic number, because the mean of its divisors is an integer number (55400400).

Almost surely, 2^221432401 is an apocalyptic number.

It is an amenable number.

221432401 is a deficient number, since it is larger than the sum of its proper divisors (169199).

221432401 is a wasteful number, since it uses less digits than its factorization.

221432401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 169198.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 221432401 is about 14880.6048600183. The cubic root of 221432401 is about 604.9884122271.

Adding to 221432401 its reverse (104234122), we get a palindrome (325666523).

The spelling of 221432401 in words is "two hundred twenty-one million, four hundred thirty-two thousand, four hundred one".