61641442565 has 8 divisors (see below), whose sum is σ = 76520411640. Its totient is φ = 47612700352.

The previous prime is 61641442549. The next prime is 61641442619. The reversal of 61641442565 is 56524414616.

It can be written as a sum of positive squares in 4 ways, for example, as 5543993764 + 56097448801 = 74458^2 + 236849^2 .

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 61641442565 - 2⁴ = 61641442549 is a prime.

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 7 ways as a sum of consecutive naturals, for example, 212556554 + ... + 212556843.

It is an arithmetic number, because the mean of its divisors is an integer number (9565051455).

Almost surely, 2^61641442565 is an apocalyptic number.

It is an amenable number.

61641442565 is a deficient number, since it is larger than the sum of its proper divisors (14878969075).

61641442565 is a wasteful number, since it uses less digits than its factorization.

61641442565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 425113431.

The product of its digits is 691200, while the sum is 44.

The spelling of 61641442565 in words is "sixty-one billion, six hundred forty-one million, four hundred forty-two thousand, five hundred sixty-five".