64028991 has 16 divisors (see below), whose sum is σ = 92252160. Its totient is φ = 39268320.

The previous prime is 64028959. The next prime is 64029029. The reversal of 64028991 is 19982046.

64028991 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 64028991 - 2⁵ = 64028959 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64028191) by changing a digit.

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 in 15 ways as a sum of consecutive naturals, for example, 9490 + ... + 14768.

It is an arithmetic number, because the mean of its divisors is an integer number (5765760).

Almost surely, 2^64028991 is an apocalyptic number.

64028991 is a deficient number, since it is larger than the sum of its proper divisors (28223169).

64028991 is a wasteful number, since it uses less digits than its factorization.

64028991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5606.

The product of its (nonzero) digits is 31104, while the sum is 39.

The square root of 64028991 is about 8001.8117323516. The cubic root of 64028991 is about 400.0603887992.

The spelling of 64028991 in words is "sixty-four million, twenty-eight thousand, nine hundred ninety-one".