1661090079640 has 32 divisors (see below), whose sum is σ = 3816972953280. Its totient is φ = 650299094272.

The previous prime is 1661090079619. The next prime is 1661090079647. The reversal of 1661090079640 is 469700901661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661090079647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 441777397 + ... + 441781156.

It is an arithmetic number, because the mean of its divisors is an integer number (119280404790).

Almost surely, 2^{1661090079640} is an apocalyptic number.

1661090079640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1661090079640 is an abundant number, since it is smaller than the sum of its proper divisors (2155882873640).

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

1661090079640 is a wasteful number, since it uses less digits than its factorization.

1661090079640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 883558611 (or 883558607 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 49.

The spelling of 1661090079640 in words is "one trillion, six hundred sixty-one billion, ninety million, seventy-nine thousand, six hundred forty".