64221649 has 4 divisors (see below), whose sum is σ = 64558080. Its totient is φ = 63885220.

The previous prime is 64221623. The next prime is 64221673. The reversal of 64221649 is 94612246.

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 64221649 - 2⁵ = 64221617 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64221049) 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, 167929 + ... + 168310.

It is an arithmetic number, because the mean of its divisors is an integer number (16139520).

Almost surely, 2^64221649 is an apocalyptic number.

It is an amenable number.

64221649 is a deficient number, since it is larger than the sum of its proper divisors (336431).

64221649 is a wasteful number, since it uses less digits than its factorization.

64221649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336430.

The product of its digits is 20736, while the sum is 34.

The square root of 64221649 is about 8013.8410890159. The cubic root of 64221649 is about 400.4612366973.

The spelling of 64221649 in words is "sixty-four million, two hundred twenty-one thousand, six hundred forty-nine".