1661156006620 has 24 divisors (see below), whose sum is σ = 3805557397488. Its totient is φ = 604056729600.

The previous prime is 1661156006569. The next prime is 1661156006651. The reversal of 1661156006620 is 266006511661.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 3775354341 + ... + 3775354780.

It is an arithmetic number, because the mean of its divisors is an integer number (158564891562).

Almost surely, 2^{1661156006620} is an apocalyptic number.

1661156006620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1661156006620 is an abundant number, since it is smaller than the sum of its proper divisors (2144401390868).

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

1661156006620 is a wasteful number, since it uses less digits than its factorization.

1661156006620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7550709141 (or 7550709139 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 40.

The spelling of 1661156006620 in words is "one trillion, six hundred sixty-one billion, one hundred fifty-six million, six thousand, six hundred twenty".