161725311072 has 384 divisors, whose sum is σ = 531685969920. Its totient is φ = 47453091840.

The previous prime is 161725311037. The next prime is 161725311109. The reversal of 161725311072 is 270113527161.

161725311072 is a `hidden beast` number, since 1 + 6 + 17 + 2 + 531 + 107 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 108758713 + ... + 108760199.

It is an arithmetic number, because the mean of its divisors is an integer number (1384598880).

Almost surely, 2^161725311072 is an apocalyptic number.

161725311072 is a gapful number since it is divisible by the number (12) 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 161725311072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (265842984960).

161725311072 is an abundant number, since it is smaller than the sum of its proper divisors (369960658848).

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

161725311072 is a wasteful number, since it uses less digits than its factorization.

161725311072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1963 (or 1949 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 36.

The spelling of 161725311072 in words is "one hundred sixty-one billion, seven hundred twenty-five million, three hundred eleven thousand, seventy-two".