66450745631 has 4 divisors (see below), whose sum is σ = 66458536200. Its totient is φ = 66442955064.

The previous prime is 66450745607. The next prime is 66450745693. The reversal of 66450745631 is 13654705466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66450745631 is a prime.

It is a super-2 number, since 2×66450745631² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66450715631) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3882476 + ... + 3899553.

It is an arithmetic number, because the mean of its divisors is an integer number (16614634050).

Almost surely, 2^66450745631 is an apocalyptic number.

66450745631 is a deficient number, since it is larger than the sum of its proper divisors (7790569).

66450745631 is an equidigital number, since it uses as much as digits as its factorization.

66450745631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7790568.

The product of its (nonzero) digits is 1814400, while the sum is 47.

The spelling of 66450745631 in words is "sixty-six billion, four hundred fifty million, seven hundred forty-five thousand, six hundred thirty-one".