6561606615 has 16 divisors (see below), whose sum is σ = 10500921216. Its totient is φ = 3498740000.

The previous prime is 6561606593. The next prime is 6561606631. The reversal of 6561606615 is 5166061656.

It is a de Polignac number, because none of the positive numbers 2^k-6561606615 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23740 + ... + 116990.

It is an arithmetic number, because the mean of its divisors is an integer number (656307576).

Almost surely, 2^6561606615 is an apocalyptic number.

6561606615 is a deficient number, since it is larger than the sum of its proper divisors (3939314601).

6561606615 is a wasteful number, since it uses less digits than its factorization.

6561606615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97950.

The product of its (nonzero) digits is 194400, while the sum is 42.

The square root of 6561606615 is about 81003.7444504882. The cubic root of 6561606615 is about 1872.1331349014.

The spelling of 6561606615 in words is "six billion, five hundred sixty-one million, six hundred six thousand, six hundred fifteen".