661707967284 has 480 divisors, whose sum is σ = 2191677143040. Its totient is φ = 169454529792.

The previous prime is 661707967259. The next prime is 661707967307. The reversal of 661707967284 is 482769707166.

661707967284 is a `hidden beast` number, since 6 + 617 + 0 + 7 + 9 + 6 + 7 + 2 + 8 + 4 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 144380857 + ... + 144385439.

It is an arithmetic number, because the mean of its divisors is an integer number (4565994048).

Almost surely, 2^661707967284 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 661707967284, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1095838571520).

661707967284 is an abundant number, since it is smaller than the sum of its proper divisors (1529969175756).

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

661707967284 is a wasteful number, since it uses less digits than its factorization.

661707967284 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4761 (or 4750 counting only the distinct ones).

The product of its (nonzero) digits is 42674688, while the sum is 63.

The spelling of 661707967284 in words is "six hundred sixty-one billion, seven hundred seven million, nine hundred sixty-seven thousand, two hundred eighty-four".