64878569820 has 144 divisors (see below), whose sum is σ = 214006822848. Its totient is φ = 15843133440.

The previous prime is 64878569761. The next prime is 64878569831. The reversal of 64878569820 is 2896587846.

64878569820 is a `hidden beast` number, since 6 + 48 + 7 + 8 + 569 + 8 + 20 = 666.

It is a super-2 number, since 2×64878569820² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 47 ways as a sum of consecutive naturals, for example, 173296 + ... + 399735.

It is an arithmetic number, because the mean of its divisors is an integer number (1486158492).

Almost surely, 2^64878569820 is an apocalyptic number.

64878569820 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

64878569820 is an abundant number, since it is smaller than the sum of its proper divisors (149128253028).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

64878569820 is a wasteful number, since it uses less digits than its factorization.

64878569820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 573100 (or 573095 counting only the distinct ones).

The product of its (nonzero) digits is 46448640, while the sum is 63.

The spelling of 64878569820 in words is "sixty-four billion, eight hundred seventy-eight million, five hundred sixty-nine thousand, eight hundred twenty".