66787822871256 has 64 divisors (see below), whose sum is σ = 167099451840000. Its totient is φ = 22245294549888.

The previous prime is 66787822871251. The next prime is 66787822871309. The reversal of 66787822871256 is 65217822878766.

It is a super-2 number, since 2×66787822871256² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66787822871251) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 174297331 + ... + 174680093.

It is an arithmetic number, because the mean of its divisors is an integer number (2610928935000).

Almost surely, 2^{66787822871256} is an apocalyptic number.

It is an amenable number.

66787822871256 is an abundant number, since it is smaller than the sum of its proper divisors (100311628968744).

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

66787822871256 is a wasteful number, since it uses less digits than its factorization.

66787822871256 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 388408 (or 388404 counting only the distinct ones).

The product of its digits is 1517322240, while the sum is 75.

The spelling of 66787822871256 in words is "sixty-six trillion, seven hundred eighty-seven billion, eight hundred twenty-two million, eight hundred seventy-one thousand, two hundred fifty-six".