155661791796 has 480 divisors, whose sum is σ = 523623260160. Its totient is φ = 39251506176.

The previous prime is 155661791771. The next prime is 155661791821. The reversal of 155661791796 is 697197166551.

155661791796 is a `hidden beast` number, since 1 + 5 + 5 + 6 + 617 + 9 + 1 + 7 + 9 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (155661791771) and next prime (155661791821).

It is a Harshad number since it is a multiple of its sum of digits (63).

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 159 ways as a sum of consecutive naturals, for example, 75453061 + ... + 75455123.

It is an arithmetic number, because the mean of its divisors is an integer number (1090881792).

Almost surely, 2^155661791796 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 155661791796, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (261811630080).

155661791796 is an abundant number, since it is smaller than the sum of its proper divisors (367961468364).

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

155661791796 is a wasteful number, since it uses less digits than its factorization.

155661791796 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2225 (or 2214 counting only the distinct ones).

The product of its digits is 21432600, while the sum is 63.

The spelling of 155661791796 in words is "one hundred fifty-five billion, six hundred sixty-one million, seven hundred ninety-one thousand, seven hundred ninety-six".