661183776 has 192 divisors, whose sum is σ = 2134823040. Its totient is φ = 197406720.

The previous prime is 661183711. The next prime is 661183799. The reversal of 661183776 is 677381166.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 693316 + ... + 694268.

It is an arithmetic number, because the mean of its divisors is an integer number (11118870).

Almost surely, 2^661183776 is an apocalyptic number.

661183776 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661183776, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1067411520).

661183776 is an abundant number, since it is smaller than the sum of its proper divisors (1473639264).

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

661183776 is a wasteful number, since it uses less digits than its factorization.

661183776 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1056 (or 1042 counting only the distinct ones).

The product of its digits is 254016, while the sum is 45.

The square root of 661183776 is about 25713.4940449562. The cubic root of 661183776 is about 871.1789960710.

The spelling of 661183776 in words is "six hundred sixty-one million, one hundred eighty-three thousand, seven hundred seventy-six".