661606342544 has 60 divisors (see below), whose sum is σ = 1491905191644. Its totient is φ = 283401199872.

The previous prime is 661606342541. The next prime is 661606342549. The reversal of 661606342544 is 445243606166.

661606342544 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 2 ways, for example, as 483319724944 + 178286617600 = 695212^2 + 422240^2 .

It is not an unprimeable number, because it can be changed into a prime (661606342541) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1332974 + ... + 1760690.

Almost surely, 2^661606342544 is an apocalyptic number.

It is an amenable number.

661606342544 is an abundant number, since it is smaller than the sum of its proper divisors (830298849100).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661606342544 is a wasteful number, since it uses less digits than its factorization.

661606342544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 429712 (or 429699 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 47.

The spelling of 661606342544 in words is "six hundred sixty-one billion, six hundred six million, three hundred forty-two thousand, five hundred forty-four".