66403540791 has 12 divisors (see below), whose sum is σ = 109618543632. Its totient is φ = 37944880416.

The previous prime is 66403540769. The next prime is 66403540823. The reversal of 66403540791 is 19704530466.

66403540791 is a `hidden beast` number, since 66 + 40 + 3 + 540 + 7 + 9 + 1 = 666.

It is not a de Polignac number, because 66403540791 - 2¹⁰ = 66403539767 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66403540751) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 527012166 + ... + 527012291.

It is an arithmetic number, because the mean of its divisors is an integer number (9134878636).

Almost surely, 2^66403540791 is an apocalyptic number.

66403540791 is a deficient number, since it is larger than the sum of its proper divisors (43215002841).

66403540791 is a wasteful number, since it uses less digits than its factorization.

66403540791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1054024470 (or 1054024467 counting only the distinct ones).

The product of its (nonzero) digits is 544320, while the sum is 45.

The spelling of 66403540791 in words is "sixty-six billion, four hundred three million, five hundred forty thousand, seven hundred ninety-one".