661243002650 has 48 divisors (see below), whose sum is σ = 1272449852640. Its totient is φ = 255351096000.

The previous prime is 661243002647. The next prime is 661243002697. The reversal of 661243002650 is 56200342166.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 661243002650.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21518597 + ... + 21549303.

It is an arithmetic number, because the mean of its divisors is an integer number (26509371930).

Almost surely, 2^661243002650 is an apocalyptic number.

661243002650 is a deficient number, since it is larger than the sum of its proper divisors (611206849990).

661243002650 is a wasteful number, since it uses less digits than its factorization.

661243002650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45599 (or 45594 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 35.

The spelling of 661243002650 in words is "six hundred sixty-one billion, two hundred forty-three million, two thousand, six hundred fifty".