1061661156666 has 96 divisors (see below), whose sum is σ = 2434028803584. Its totient is φ = 308127283200.

The previous prime is 1061661156643. The next prime is 1061661156667. The reversal of 1061661156666 is 6666511661601.

It is a super-2 number, since 2×1061661156666² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1061661156667) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1939926 + ... + 2426238.

It is an arithmetic number, because the mean of its divisors is an integer number (25354466704).

Almost surely, 2^{1061661156666} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1061661156666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1217014401792).

1061661156666 is an abundant number, since it is smaller than the sum of its proper divisors (1372367646918).

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

1061661156666 is a wasteful number, since it uses less digits than its factorization.

1061661156666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 486468 (or 486457 counting only the distinct ones).

The product of its (nonzero) digits is 1399680, while the sum is 51.

The spelling of 1061661156666 in words is "one trillion, sixty-one billion, six hundred sixty-one million, one hundred fifty-six thousand, six hundred sixty-six".