666562780 has 48 divisors (see below), whose sum is σ = 1542540384. Its totient is φ = 240387840.

The previous prime is 666562777. The next prime is 666562849. The reversal of 666562780 is 87265666.

It is a self number, because there is not a number n which added to its sum of digits gives 666562780.

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, 18631 + ... + 40990.

It is an arithmetic number, because the mean of its divisors is an integer number (32136258).

Almost surely, 2^666562780 is an apocalyptic number.

It is an amenable number.

666562780 is an abundant number, since it is smaller than the sum of its proper divisors (875977604).

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

666562780 is a wasteful number, since it uses less digits than its factorization.

666562780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59686 (or 59684 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 46.

The square root of 666562780 is about 25817.8771396875. The cubic root of 666562780 is about 873.5350856978.

The spelling of 666562780 in words is "six hundred sixty-six million, five hundred sixty-two thousand, seven hundred eighty".