66450745637 has 4 divisors (see below), whose sum is σ = 66451884780. Its totient is φ = 66449606496.

The previous prime is 66450745607. The next prime is 66450745693. The reversal of 66450745637 is 73654705466.

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

It can be written as a sum of positive squares in 2 ways, for example, as 66233654881 + 217090756 = 257359^2 + 14734^2 .

It is a cyclic number.

It is not a de Polignac number, because 66450745637 - 2²⁶ = 66383636773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66450745607) 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, 477062 + ... + 600407.

It is an arithmetic number, because the mean of its divisors is an integer number (16612971195).

Almost surely, 2^66450745637 is an apocalyptic number.

It is an amenable number.

66450745637 is a deficient number, since it is larger than the sum of its proper divisors (1139143).

66450745637 is a wasteful number, since it uses less digits than its factorization.

66450745637 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1139142.

The product of its (nonzero) digits is 12700800, while the sum is 53.

The spelling of 66450745637 in words is "sixty-six billion, four hundred fifty million, seven hundred forty-five thousand, six hundred thirty-seven".