64720539 has 20 divisors (see below), whose sum is σ = 104120016. Its totient is φ = 39827376.

The previous prime is 64720531. The next prime is 64720543. The reversal of 64720539 is 93502746.

64720539 is a `hidden beast` number, since 647 + 2 + 0 + 5 + 3 + 9 = 666.

It is not a de Polignac number, because 64720539 - 2³ = 64720531 is a prime.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (64720531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 29679 + ... + 31784.

Almost surely, 2^64720539 is an apocalyptic number.

64720539 is a deficient number, since it is larger than the sum of its proper divisors (39399477).

64720539 is a wasteful number, since it uses less digits than its factorization.

64720539 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61488 (or 61479 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 36.

The square root of 64720539 is about 8044.9076439696. The cubic root of 64720539 is about 401.4955244646.

The spelling of 64720539 in words is "sixty-four million, seven hundred twenty thousand, five hundred thirty-nine".