64438666 has 4 divisors (see below), whose sum is σ = 96658002. Its totient is φ = 32219332.

The previous prime is 64438637. The next prime is 64438711. The reversal of 64438666 is 66683446.

64438666 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 an emirpimes, since its reverse is a distinct semiprime: 66683446 = 2 ⋅33341723.

It can be written as a sum of positive squares in only one way, i.e., 58293225 + 6145441 = 7635^2 + 2479^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16109665 + ... + 16109668.

Almost surely, 2^64438666 is an apocalyptic number.

64438666 is a deficient number, since it is larger than the sum of its proper divisors (32219336).

64438666 is a wasteful number, since it uses less digits than its factorization.

64438666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32219335.

The product of its digits is 497664, while the sum is 43.

The square root of 64438666 is about 8027.3698058580. The cubic root of 64438666 is about 400.9118074387.

The spelling of 64438666 in words is "sixty-four million, four hundred thirty-eight thousand, six hundred sixty-six".