65215221 has 4 divisors (see below), whose sum is σ = 86953632. Its totient is φ = 43476812.

The previous prime is 65215217. The next prime is 65215243. The reversal of 65215221 is 12251256.

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 65215221 - 2² = 65215217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 65215191 and 65215200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65215021) 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, 10869201 + ... + 10869206.

It is an arithmetic number, because the mean of its divisors is an integer number (21738408).

Almost surely, 2^65215221 is an apocalyptic number.

It is an amenable number.

65215221 is a deficient number, since it is larger than the sum of its proper divisors (21738411).

65215221 is a wasteful number, since it uses less digits than its factorization.

65215221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21738410.

The product of its digits is 1200, while the sum is 24.

The square root of 65215221 is about 8075.5941577075. The cubic root of 65215221 is about 402.5158534450.

Adding to 65215221 its reverse (12251256), we get a palindrome (77466477).

The spelling of 65215221 in words is "sixty-five million, two hundred fifteen thousand, two hundred twenty-one".