661616260646 has 32 divisors (see below), whose sum is σ = 1122914564640. Its totient is φ = 289709568000.

The previous prime is 661616260601. The next prime is 661616260661. The reversal of 661616260646 is 646062616166.

661616260646 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 661616260594 and 661616260603.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3941531 + ... + 4105958.

It is an arithmetic number, because the mean of its divisors is an integer number (35091080145).

Almost surely, 2^661616260646 is an apocalyptic number.

661616260646 is a deficient number, since it is larger than the sum of its proper divisors (461298303994).

661616260646 is a wasteful number, since it uses less digits than its factorization.

661616260646 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8047640.

The product of its (nonzero) digits is 2239488, while the sum is 50.

The spelling of 661616260646 in words is "six hundred sixty-one billion, six hundred sixteen million, two hundred sixty thousand, six hundred forty-six".