64890742855 has 4 divisors (see below), whose sum is σ = 77868891432. Its totient is φ = 51912594280.

The previous prime is 64890742853. The next prime is 64890742913. The reversal of 64890742855 is 55824709846.

64890742855 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.

It is not a de Polignac number, because 64890742855 - 2¹ = 64890742853 is a prime.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 64890742855.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64890742853) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6489074281 + ... + 6489074290.

It is an arithmetic number, because the mean of its divisors is an integer number (19467222858).

Almost surely, 2^64890742855 is an apocalyptic number.

64890742855 is a deficient number, since it is larger than the sum of its proper divisors (12978148577).

64890742855 is a wasteful number, since it uses less digits than its factorization.

64890742855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12978148576.

The product of its (nonzero) digits is 19353600, while the sum is 58.

The spelling of 64890742855 in words is "sixty-four billion, eight hundred ninety million, seven hundred forty-two thousand, eight hundred fifty-five".