2661661131560 has 64 divisors (see below), whose sum is σ = 6067620392400. Its totient is φ = 1050703036416.

The previous prime is 2661661131559. The next prime is 2661661131581. The reversal of 2661661131560 is 651311661662.

It can be written as a sum of positive squares in 8 ways, for example, as 475385428324 + 2186275703236 = 689482^2 + 1478606^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 397976 + ... + 2341304.

Almost surely, 2^{2661661131560} is an apocalyptic number.

2661661131560 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2661661131560 is an abundant number, since it is smaller than the sum of its proper divisors (3405959260840).

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

2661661131560 is a wasteful number, since it uses less digits than its factorization.

2661661131560 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1943790 (or 1943786 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 44.

The spelling of 2661661131560 in words is "two trillion, six hundred sixty-one billion, six hundred sixty-one million, one hundred thirty-one thousand, five hundred sixty".