66641521453 has 8 divisors (see below), whose sum is σ = 71778539448. Its totient is φ = 61506038784.

The previous prime is 66641521447. The next prime is 66641521487. The reversal of 66641521453 is 35412514666.

66641521453 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 19353539689 + 47287981764 = 139117^2 + 217458^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66641521453 - 2⁵ = 66641521421 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 (66641521423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 292876 + ... + 468037.

It is an arithmetic number, because the mean of its divisors is an integer number (8972317431).

Almost surely, 2^66641521453 is an apocalyptic number.

It is an amenable number.

66641521453 is a deficient number, since it is larger than the sum of its proper divisors (5137017995).

66641521453 is a wasteful number, since it uses less digits than its factorization.

66641521453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 767663.

The product of its digits is 518400, while the sum is 43.

The spelling of 66641521453 in words is "sixty-six billion, six hundred forty-one million, five hundred twenty-one thousand, four hundred fifty-three".