661450780 has 12 divisors (see below), whose sum is σ = 1389046680. Its totient is φ = 264580304.

The previous prime is 661450753. The next prime is 661450799. The reversal of 661450780 is 87054166.

661450780 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16536250 + ... + 16536289.

It is an arithmetic number, because the mean of its divisors is an integer number (115753890).

Almost surely, 2^661450780 is an apocalyptic number.

It is an amenable number.

661450780 is an abundant number, since it is smaller than the sum of its proper divisors (727595900).

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

661450780 is a wasteful number, since it uses less digits than its factorization.

661450780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33072548 (or 33072546 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 661450780 is about 25718.6854251923. The cubic root of 661450780 is about 871.2962488837.

The spelling of 661450780 in words is "six hundred sixty-one million, four hundred fifty thousand, seven hundred eighty".