6511115505661 has 32 divisors (see below), whose sum is σ = 7446367272960. Its totient is φ = 5647946487744.

The previous prime is 6511115505637. The next prime is 6511115505673. The reversal of 6511115505661 is 1665055111156.

It is a cyclic number.

It is not a de Polignac number, because 6511115505661 - 2¹⁹ = 6511114981373 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 (6511115505161) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3709380 + ... + 5175106.

It is an arithmetic number, because the mean of its divisors is an integer number (232698977280).

Almost surely, 2^{6511115505661} is an apocalyptic number.

It is an amenable number.

6511115505661 is a deficient number, since it is larger than the sum of its proper divisors (935251767299).

6511115505661 is a wasteful number, since it uses less digits than its factorization.

6511115505661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1466025.

The product of its (nonzero) digits is 135000, while the sum is 43.

The spelling of 6511115505661 in words is "six trillion, five hundred eleven billion, one hundred fifteen million, five hundred five thousand, six hundred sixty-one".