1661426312040 has 192 divisors, whose sum is σ = 5908312238400. Its totient is φ = 401552870400.

The previous prime is 1661426312011. The next prime is 1661426312041. The reversal of 1661426312040 is 402136241661.

1661426312040 is a `hidden beast` number, since 1 + 6 + 6 + 14 + 2 + 631 + 2 + 0 + 4 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 1661426311986 and 1661426312004.

It is not an unprimeable number, because it can be changed into a prime (1661426312041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 676996 + ... + 1944524.

It is an arithmetic number, because the mean of its divisors is an integer number (30772459575).

Almost surely, 2^{1661426312040} is an apocalyptic number.

1661426312040 is a gapful number since it is divisible by the number (10) 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 1661426312040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2954156119200).

1661426312040 is an abundant number, since it is smaller than the sum of its proper divisors (4246885926360).

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

1661426312040 is a wasteful number, since it uses less digits than its factorization.

1661426312040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1267888 (or 1267881 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The spelling of 1661426312040 in words is "one trillion, six hundred sixty-one billion, four hundred twenty-six million, three hundred twelve thousand, forty".