6611561616 has 160 divisors (see below), whose sum is σ = 19094777856. Its totient is φ = 1954368000.

The previous prime is 6611561599. The next prime is 6611561687. The reversal of 6611561616 is 6161651166.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4218465 + ... + 4220031.

Almost surely, 2^6611561616 is an apocalyptic number.

6611561616 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 6611561616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (9547388928).

6611561616 is an abundant number, since it is smaller than the sum of its proper divisors (12483216240).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

6611561616 is a wasteful number, since it uses less digits than its factorization.

6611561616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1781 (or 1775 counting only the distinct ones).

The product of its digits is 38880, while the sum is 39.

The square root of 6611561616 is about 81311.5097387818. The cubic root of 6611561616 is about 1876.8721203904.

The spelling of 6611561616 in words is "six billion, six hundred eleven million, five hundred sixty-one thousand, six hundred sixteen".