66633247491 has 32 divisors (see below), whose sum is σ = 94368552960. Its totient is φ = 41734877184.

The previous prime is 66633247469. The next prime is 66633247529. The reversal of 66633247491 is 19474233666.

It is a happy number.

66633247491 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 66633247491 - 2¹⁵ = 66633214723 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66633247451) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1020375 + ... + 1083711.

It is an arithmetic number, because the mean of its divisors is an integer number (2949017280).

Almost surely, 2^66633247491 is an apocalyptic number.

66633247491 is a deficient number, since it is larger than the sum of its proper divisors (27735305469).

66633247491 is a wasteful number, since it uses less digits than its factorization.

66633247491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63635.

The product of its digits is 3919104, while the sum is 51.

The spelling of 66633247491 in words is "sixty-six billion, six hundred thirty-three million, two hundred forty-seven thousand, four hundred ninety-one".