221065421 has 4 divisors (see below), whose sum is σ = 221113344. Its totient is φ = 221017500.

The previous prime is 221065381. The next prime is 221065423. The reversal of 221065421 is 124560122.

It is a happy number.

221065421 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, 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 221065421 - 2¹⁸ = 220803277 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221065423) 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, 16205 + ... + 26546.

It is an arithmetic number, because the mean of its divisors is an integer number (55278336).

Almost surely, 2^221065421 is an apocalyptic number.

It is an amenable number.

221065421 is a deficient number, since it is larger than the sum of its proper divisors (47923).

221065421 is an equidigital number, since it uses as much as digits as its factorization.

221065421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47922.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 221065421 is about 14868.2689308473. The cubic root of 221065421 is about 604.6540115852.

The spelling of 221065421 in words is "two hundred twenty-one million, sixty-five thousand, four hundred twenty-one".