65557776661 has 8 divisors (see below), whose sum is σ = 70631585024. Its totient is φ = 60488382960.

The previous prime is 65557776653. The next prime is 65557776667. The reversal of 65557776661 is 16667775556.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 65557776661 - 2³ = 65557776653 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 65557776661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65557776667) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1072785 + ... + 1132246.

It is an arithmetic number, because the mean of its divisors is an integer number (8828948128).

Almost surely, 2^65557776661 is an apocalyptic number.

It is an amenable number.

65557776661 is a deficient number, since it is larger than the sum of its proper divisors (5073808363).

65557776661 is a wasteful number, since it uses less digits than its factorization.

65557776661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2207331.

The product of its digits is 55566000, while the sum is 61.

The spelling of 65557776661 in words is "sixty-five billion, five hundred fifty-seven million, seven hundred seventy-six thousand, six hundred sixty-one".