661675776 has 144 divisors (see below), whose sum is σ = 1879041024. Its totient is φ = 206221312.

The previous prime is 661675771. The next prime is 661675783. The reversal of 661675776 is 677576166.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661675771) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 829810 + ... + 830606.

It is an arithmetic number, because the mean of its divisors is an integer number (13048896).

Almost surely, 2^661675776 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 661675776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (939520512).

661675776 is an abundant number, since it is smaller than the sum of its proper divisors (1217365248).

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

661675776 is a wasteful number, since it uses less digits than its factorization.

661675776 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 886 (or 872 counting only the distinct ones).

The product of its digits is 2222640, while the sum is 51.

The square root of 661675776 is about 25723.0592270826. The cubic root of 661675776 is about 871.3950297017.

The spelling of 661675776 in words is "six hundred sixty-one million, six hundred seventy-five thousand, seven hundred seventy-six".