661774716 has 18 divisors (see below), whose sum is σ = 1672819512. Its totient is φ = 220591560.

The previous prime is 661774681. The next prime is 661774747. The reversal of 661774716 is 617477166.

661774716 is a `hidden beast` number, since 6 + 6 + 177 + 471 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is a congruent number.

It is an unprimeable number.

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, 9191280 + ... + 9191351.

Almost surely, 2^661774716 is an apocalyptic number.

It is an amenable number.

661774716 is an abundant number, since it is smaller than the sum of its proper divisors (1011044796).

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

661774716 is a wasteful number, since it uses less digits than its factorization.

661774716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18382641 (or 18382636 counting only the distinct ones).

The product of its digits is 296352, while the sum is 45.

The square root of 661774716 is about 25724.9823323554. The cubic root of 661774716 is about 871.4384606037.

The spelling of 661774716 in words is "six hundred sixty-one million, seven hundred seventy-four thousand, seven hundred sixteen".