64005639 has 8 divisors (see below), whose sum is σ = 88283760. Its totient is φ = 41198976.

The previous prime is 64005541. The next prime is 64005647. The reversal of 64005639 is 93650046.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 64005639 - 2¹² = 64001543 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64005659) 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, 367762 + ... + 367935.

It is an arithmetic number, because the mean of its divisors is an integer number (11035470).

Almost surely, 2^64005639 is an apocalyptic number.

64005639 is a deficient number, since it is larger than the sum of its proper divisors (24278121).

64005639 is a wasteful number, since it uses less digits than its factorization.

64005639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 735729.

The product of its (nonzero) digits is 19440, while the sum is 33.

The square root of 64005639 is about 8000.3524297371. The cubic root of 64005639 is about 400.0117475716.

The spelling of 64005639 in words is "sixty-four million, five thousand, six hundred thirty-nine".