636427688048778 has 16 divisors (see below), whose sum is σ = 1296871515269856. Its totient is φ = 208139872820880.

The previous prime is 636427688048743. The next prime is 636427688048843. The reversal of 636427688048778 is 877840886724636.

It is a happy number.

It is a super-3 number, since 3×636427688048778³ (a number of 45 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 636427688048778.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1000672465168 + ... + 1000672465803.

It is an arithmetic number, because the mean of its divisors is an integer number (81054469704366).

Almost surely, 2^{636427688048778} is an apocalyptic number.

636427688048778 is an abundant number, since it is smaller than the sum of its proper divisors (660443827221078).

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

636427688048778 is a wasteful number, since it uses less digits than its factorization.

636427688048778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2001344931029.

The product of its (nonzero) digits is 29132587008, while the sum is 84.

The spelling of 636427688048778 in words is "six hundred thirty-six trillion, four hundred twenty-seven billion, six hundred eighty-eight million, forty-eight thousand, seven hundred seventy-eight".