6165121015661 has 4 divisors (see below), whose sum is σ = 6167671750812. Its totient is φ = 6162570280512.

The previous prime is 6165121015609. The next prime is 6165121015687. The reversal of 6165121015661 is 1665101215616.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3555826776100 + 2609294239561 = 1885690^2 + 1615331^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6165121015661 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 (6165121015861) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1275363950 + ... + 1275368783.

It is an arithmetic number, because the mean of its divisors is an integer number (1541917937703).

Almost surely, 2^{6165121015661} is an apocalyptic number.

It is an amenable number.

6165121015661 is a deficient number, since it is larger than the sum of its proper divisors (2550735151).

6165121015661 is a wasteful number, since it uses less digits than its factorization.

6165121015661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2550735150.

The product of its (nonzero) digits is 64800, while the sum is 41.

The spelling of 6165121015661 in words is "six trillion, one hundred sixty-five billion, one hundred twenty-one million, fifteen thousand, six hundred sixty-one".