661198874742 has 96 divisors (see below), whose sum is σ = 1698831463680. Its totient is φ = 181848300480.

The previous prime is 661198874723. The next prime is 661198874747. The reversal of 661198874742 is 247478891166.

661198874742 is a `hidden beast` number, since 6 + 611 + 9 + 8 + 8 + 7 + 4 + 7 + 4 + 2 = 666.

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

It is a self number, because there is not a number n which added to its sum of digits gives 661198874742.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661198874747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 936133 + ... + 1482815.

It is an arithmetic number, because the mean of its divisors is an integer number (17696161080).

Almost surely, 2^661198874742 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661198874742, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (849415731840).

661198874742 is an abundant number, since it is smaller than the sum of its proper divisors (1037632588938).

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

661198874742 is a wasteful number, since it uses less digits than its factorization.

661198874742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 547058 (or 547055 counting only the distinct ones).

The product of its digits is 32514048, while the sum is 63.

The spelling of 661198874742 in words is "six hundred sixty-one billion, one hundred ninety-eight million, eight hundred seventy-four thousand, seven hundred forty-two".