661230680 has 128 divisors (see below), whose sum is σ = 1706987520. Its totient is φ = 228180480.

The previous prime is 661230679. The next prime is 661230719. The reversal of 661230680 is 86032166.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2256614 + ... + 2256906.

It is an arithmetic number, because the mean of its divisors is an integer number (13335840).

Almost surely, 2^661230680 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661230680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (853493760).

661230680 is an abundant number, since it is smaller than the sum of its proper divisors (1045756840).

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

661230680 is a wasteful number, since it uses less digits than its factorization.

661230680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 561 (or 557 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 32.

The square root of 661230680 is about 25714.4060790834. The cubic root of 661230680 is about 871.1995958976.

The spelling of 661230680 in words is "six hundred sixty-one million, two hundred thirty thousand, six hundred eighty".