6511661613 has 24 divisors (see below), whose sum is σ = 9658883520. Its totient is φ = 4224991680.

The previous prime is 6511661609. The next prime is 6511661617. The reversal of 6511661613 is 3161661156.

It is an interprime number because it is at equal distance from previous prime (6511661609) and next prime (6511661617).

It is not a de Polignac number, because 6511661613 - 2² = 6511661609 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6511661617) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 78808 + ... + 138686.

It is an arithmetic number, because the mean of its divisors is an integer number (402453480).

Almost surely, 2^6511661613 is an apocalyptic number.

It is an amenable number.

6511661613 is a deficient number, since it is larger than the sum of its proper divisors (3147221907).

6511661613 is a wasteful number, since it uses less digits than its factorization.

6511661613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60209 (or 60206 counting only the distinct ones).

The product of its digits is 19440, while the sum is 36.

The square root of 6511661613 is about 80694.8673274825. The cubic root of 6511661613 is about 1867.3709911258.

The spelling of 6511661613 in words is "six billion, five hundred eleven million, six hundred sixty-one thousand, six hundred thirteen".