65811388878 has 12 divisors (see below), whose sum is σ = 142591342608. Its totient is φ = 21937129620.

The previous prime is 65811388843. The next prime is 65811388889. The reversal of 65811388878 is 87888311856.

It is a super-2 number, since 2×65811388878² (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 (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1828094118 + ... + 1828094153.

It is an arithmetic number, because the mean of its divisors is an integer number (11882611884).

Almost surely, 2^65811388878 is an apocalyptic number.

65811388878 is an abundant number, since it is smaller than the sum of its proper divisors (76779953730).

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

65811388878 is a wasteful number, since it uses less digits than its factorization.

65811388878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3656188279 (or 3656188276 counting only the distinct ones).

The product of its digits is 20643840, while the sum is 63.

The spelling of 65811388878 in words is "sixty-five billion, eight hundred eleven million, three hundred eighty-eight thousand, eight hundred seventy-eight".