64444221 has 8 divisors (see below), whose sum is σ = 95472960. Its totient is φ = 42962796.

The previous prime is 64444213. The next prime is 64444231. The reversal of 64444221 is 12244446.

It is a happy number.

It is not a de Polignac number, because 64444221 - 2³ = 64444213 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 2386823 = 64444221 / (6 + 4 + 4 + 4 + 4 + 2 + 2 + 1).

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64444201) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1193385 + ... + 1193438.

It is an arithmetic number, because the mean of its divisors is an integer number (11934120).

Almost surely, 2^64444221 is an apocalyptic number.

It is an amenable number.

64444221 is a deficient number, since it is larger than the sum of its proper divisors (31028739).

64444221 is a wasteful number, since it uses less digits than its factorization.

64444221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2386832 (or 2386826 counting only the distinct ones).

The product of its digits is 6144, while the sum is 27.

The square root of 64444221 is about 8027.7158021445. The cubic root of 64444221 is about 400.9233274428.

Adding to 64444221 its reverse (12244446), we get a palindrome (76688667).

The spelling of 64444221 in words is "sixty-four million, four hundred forty-four thousand, two hundred twenty-one".