161961552 has 80 divisors (see below), whose sum is σ = 470594880. Its totient is φ = 53324928.

The previous prime is 161961539. The next prime is 161961557. The reversal of 161961552 is 255169161.

161961552 is a `hidden beast` number, since 16 + 1 + 96 + 1 + 552 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161961557) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33598 + ... + 38114.

It is an arithmetic number, because the mean of its divisors is an integer number (5882436).

Almost surely, 2^161961552 is an apocalyptic number.

161961552 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 161961552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (235297440).

161961552 is an abundant number, since it is smaller than the sum of its proper divisors (308633328).

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

161961552 is a wasteful number, since it uses less digits than its factorization.

161961552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4617 (or 4605 counting only the distinct ones).

The product of its digits is 16200, while the sum is 36.

The square root of 161961552 is about 12726.4115916467. The cubic root of 161961552 is about 545.0930481087.

The spelling of 161961552 in words is "one hundred sixty-one million, nine hundred sixty-one thousand, five hundred fifty-two".