66242615641 has 4 divisors (see below), whose sum is σ = 66271456692. Its totient is φ = 66213774592.

The previous prime is 66242615627. The next prime is 66242615657. The reversal of 66242615641 is 14651624266.

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 28676035600 + 37566580041 = 169340^2 + 193821^2 .

It is a cyclic number.

It is not a de Polignac number, because 66242615641 - 2⁵ = 66242615609 is a prime.

It is a super-2 number, since 2×66242615641² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66242615441) 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, 14417080 + ... + 14421673.

It is an arithmetic number, because the mean of its divisors is an integer number (16567864173).

Almost surely, 2^66242615641 is an apocalyptic number.

It is an amenable number.

66242615641 is a deficient number, since it is larger than the sum of its proper divisors (28841051).

66242615641 is a wasteful number, since it uses less digits than its factorization.

66242615641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28841050.

The product of its digits is 414720, while the sum is 43.

The spelling of 66242615641 in words is "sixty-six billion, two hundred forty-two million, six hundred fifteen thousand, six hundred forty-one".