2661117342640 has 80 divisors (see below), whose sum is σ = 6343237194336. Its totient is φ = 1037627136000.

The previous prime is 2661117342619. The next prime is 2661117342659. The reversal of 2661117342640 is 462437111662.

It is a tau number, because it is divible by the number of its divisors (80).

It is a super-2 number, since 2×2661117342640² (a number of 26 digits) contains 22 as substring.

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, 3644215 + ... + 4313065.

Almost surely, 2^{2661117342640} is an apocalyptic number.

2661117342640 is a gapful number since it is divisible by the number (20) 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 2661117342640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3171618597168).

2661117342640 is an abundant number, since it is smaller than the sum of its proper divisors (3682119851696).

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

2661117342640 is a wasteful number, since it uses less digits than its factorization.

2661117342640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 670118 (or 670112 counting only the distinct ones).

The product of its (nonzero) digits is 290304, while the sum is 43.

The spelling of 2661117342640 in words is "two trillion, six hundred sixty-one billion, one hundred seventeen million, three hundred forty-two thousand, six hundred forty".