66494386431 has 40 divisors (see below), whose sum is σ = 114064473600. Its totient is φ = 38178585360.

The previous prime is 66494386421. The next prime is 66494386447. The reversal of 66494386431 is 13468349466.

It is a happy number.

66494386431 is a `hidden beast` number, since 66 + 494 + 3 + 8 + 64 + 31 = 666.

It is not a de Polignac number, because 66494386431 - 2²² = 66490192127 is a prime.

It is a super-2 number, since 2×66494386431² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66494386411) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1946991 + ... + 1980848.

It is an arithmetic number, because the mean of its divisors is an integer number (2851611840).

Almost surely, 2^66494386431 is an apocalyptic number.

66494386431 is a deficient number, since it is larger than the sum of its proper divisors (47570087169).

66494386431 is a wasteful number, since it uses less digits than its factorization.

66494386431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3927881 (or 3927872 counting only the distinct ones).

The product of its digits is 8957952, while the sum is 54.

The spelling of 66494386431 in words is "sixty-six billion, four hundred ninety-four million, three hundred eighty-six thousand, four hundred thirty-one".