64709221 has 4 divisors (see below), whose sum is σ = 64833472. Its totient is φ = 64584972.

The previous prime is 64709219. The next prime is 64709243. The reversal of 64709221 is 12290746.

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 64709221 - 2¹ = 64709219 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 (64709201) 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, 61341 + ... + 62386.

It is an arithmetic number, because the mean of its divisors is an integer number (16208368).

Almost surely, 2^64709221 is an apocalyptic number.

It is an amenable number.

64709221 is a deficient number, since it is larger than the sum of its proper divisors (124251).

64709221 is a wasteful number, since it uses less digits than its factorization.

64709221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124250.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 64709221 is about 8044.2041868665. The cubic root of 64709221 is about 401.4721192657.

Adding to 64709221 its reverse (12290746), we get a palindrome (76999967).

The spelling of 64709221 in words is "sixty-four million, seven hundred nine thousand, two hundred twenty-one".