661554782 has 12 divisors (see below), whose sum is σ = 1154345760. Its totient is φ = 283523436.

The previous prime is 661554781. The next prime is 661554791. The reversal of 661554782 is 287455166.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661554781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3375182 + ... + 3375377.

It is an arithmetic number, because the mean of its divisors is an integer number (96195480).

Almost surely, 2^661554782 is an apocalyptic number.

661554782 is a deficient number, since it is larger than the sum of its proper divisors (492790978).

661554782 is a wasteful number, since it uses less digits than its factorization.

661554782 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6750575 (or 6750568 counting only the distinct ones).

The product of its digits is 403200, while the sum is 44.

The square root of 661554782 is about 25720.7072608822. The cubic root of 661554782 is about 871.3419120464.

The spelling of 661554782 in words is "six hundred sixty-one million, five hundred fifty-four thousand, seven hundred eighty-two".