155161681920 has 1344 divisors, whose sum is σ = 680115211776. Its totient is φ = 33124515840.

The previous prime is 155161681889. The next prime is 155161681967. The reversal of 155161681920 is 29186161551.

155161681920 is a `hidden beast` number, since 1 + 5 + 5 + 1 + 616 + 8 + 1 + 9 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (1344).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1184440255 + ... + 1184440385.

It is an arithmetic number, because the mean of its divisors is an integer number (506038104).

Almost surely, 2^155161681920 is an apocalyptic number.

155161681920 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 155161681920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (340057605888).

155161681920 is an abundant number, since it is smaller than the sum of its proper divisors (524953529856).

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

155161681920 is an equidigital number, since it uses as much as digits as its factorization.

155161681920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 201 (or 165 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 45.

The spelling of 155161681920 in words is "one hundred fifty-five billion, one hundred sixty-one million, six hundred eighty-one thousand, nine hundred twenty".