1661607323136 has 100 divisors (see below), whose sum is σ = 4959460465212. Its totient is φ = 553869093888.

The previous prime is 1661607323119. The next prime is 1661607323143. The reversal of 1661607323136 is 6313237061661.

1661607323136 is a `hidden beast` number, since 1 + 6 + 6 + 1 + 607 + 3 + 2 + 3 + 1 + 36 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 1661607323091 and 1661607323100.

It is a congruent number.

It is an unprimeable number.

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 9 ways as a sum of consecutive naturals, for example, 19991410 + ... + 20074353.

Almost surely, 2^{1661607323136} is an apocalyptic number.

1661607323136 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

1661607323136 is an abundant number, since it is smaller than the sum of its proper divisors (3297853142076).

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

1661607323136 is an frugal number, since it uses more digits than its factorization.

1661607323136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40065793 (or 40065768 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 45.

The spelling of 1661607323136 in words is "one trillion, six hundred sixty-one billion, six hundred seven million, three hundred twenty-three thousand, one hundred thirty-six".