661117782 has 32 divisors (see below), whose sum is σ = 1426596192. Its totient is φ = 203042304.

The previous prime is 661117747. The next prime is 661117783. The reversal of 661117782 is 287711166.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 661117782.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661117783) 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 15 ways as a sum of consecutive naturals, for example, 35838 + ... + 51054.

It is an arithmetic number, because the mean of its divisors is an integer number (44581131).

Almost surely, 2^661117782 is an apocalyptic number.

661117782 is an abundant number, since it is smaller than the sum of its proper divisors (765478410).

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

661117782 is a wasteful number, since it uses less digits than its factorization.

661117782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15792.

The product of its digits is 28224, while the sum is 39.

The square root of 661117782 is about 25712.2107567591. The cubic root of 661117782 is about 871.1500104335.

The spelling of 661117782 in words is "six hundred sixty-one million, one hundred seventeen thousand, seven hundred eighty-two".