66131612426550 has 96 divisors (see below), whose sum is σ = 178938215078400. Its totient is φ = 16029921846400.

The previous prime is 66131612426549. The next prime is 66131612426651. The reversal of 66131612426550 is 5562421613166.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 66131612426550.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 10877251 + ... + 15829649.

It is an arithmetic number, because the mean of its divisors is an integer number (1863939740400).

Almost surely, 2^{66131612426550} is an apocalyptic number.

66131612426550 is an abundant number, since it is smaller than the sum of its proper divisors (112806602651850).

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

66131612426550 is a wasteful number, since it uses less digits than its factorization.

66131612426550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4960518 (or 4960513 counting only the distinct ones).

The product of its (nonzero) digits is 1555200, while the sum is 48.

The spelling of 66131612426550 in words is "sixty-six trillion, one hundred thirty-one billion, six hundred twelve million, four hundred twenty-six thousand, five hundred fifty".