661252716 has 18 divisors (see below), whose sum is σ = 1671500012. Its totient is φ = 220417560.

The previous prime is 661252703. The next prime is 661252717. The reversal of 661252716 is 617252166.

It is a happy number.

661252716 is a `hidden beast` number, since 6 + 612 + 5 + 27 + 16 = 666.

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

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 18368131 = 661252716 / (6 + 6 + 1 + 2 + 5 + 2 + 7 + 1 + 6).

It is not an unprimeable number, because it can be changed into a prime (661252717) 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, 9184030 + ... + 9184101.

Almost surely, 2^661252716 is an apocalyptic number.

It is an amenable number.

661252716 is an abundant number, since it is smaller than the sum of its proper divisors (1010247296).

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

661252716 is a wasteful number, since it uses less digits than its factorization.

661252716 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18368141 (or 18368136 counting only the distinct ones).

The product of its digits is 30240, while the sum is 36.

The square root of 661252716 is about 25714.8345512858. The cubic root of 661252716 is about 871.2092735797.

The spelling of 661252716 in words is "six hundred sixty-one million, two hundred fifty-two thousand, seven hundred sixteen".