64728551 has 8 divisors (see below), whose sum is σ = 67160880. Its totient is φ = 62309632.

The previous prime is 64728523. The next prime is 64728581. The reversal of 64728551 is 15582746.

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

It is a de Polignac number, because none of the positive numbers 2^k-64728551 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64728511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7076 + ... + 13398.

It is an arithmetic number, because the mean of its divisors is an integer number (8395110).

Almost surely, 2^64728551 is an apocalyptic number.

64728551 is a deficient number, since it is larger than the sum of its proper divisors (2432329).

64728551 is a wasteful number, since it uses less digits than its factorization.

64728551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6705.

The product of its digits is 67200, while the sum is 38.

The square root of 64728551 is about 8045.4055833128. The cubic root of 64728551 is about 401.5120913302.

The spelling of 64728551 in words is "sixty-four million, seven hundred twenty-eight thousand, five hundred fifty-one".