61601236661 has 8 divisors (see below), whose sum is σ = 62504022744. Its totient is φ = 60700043520.

The previous prime is 61601236649. The next prime is 61601236687. The reversal of 61601236661 is 16663210616.

It can be written as a sum of positive squares in 4 ways, for example, as 22535714161 + 39065522500 = 150119^2 + 197650^2 .

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 61601236661 - 2¹⁰ = 61601235637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61601296661) 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, 320216 + ... + 475121.

It is an arithmetic number, because the mean of its divisors is an integer number (7813002843).

Almost surely, 2^61601236661 is an apocalyptic number.

It is an amenable number.

61601236661 is a deficient number, since it is larger than the sum of its proper divisors (902786083).

61601236661 is a wasteful number, since it uses less digits than its factorization.

61601236661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 796471.

The product of its (nonzero) digits is 46656, while the sum is 38.

The spelling of 61601236661 in words is "sixty-one billion, six hundred one million, two hundred thirty-six thousand, six hundred sixty-one".