161187840 has 384 divisors, whose sum is σ = 636854400. Its totient is φ = 38338560.

The previous prime is 161187839. The next prime is 161187853. The reversal of 161187840 is 48781161.

It is a tau number, because it is divible by the number of its divisors (384).

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

It is a junction number, because it is equal to n+sod(n) for n = 161187795 and 161187804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3041254 + ... + 3041306.

It is an arithmetic number, because the mean of its divisors is an integer number (1658475).

Almost surely, 2^161187840 is an apocalyptic number.

161187840 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 161187840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (318427200).

161187840 is an abundant number, since it is smaller than the sum of its proper divisors (475666560).

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

161187840 is a wasteful number, since it uses less digits than its factorization.

161187840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100 (or 74 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 36.

The square root of 161187840 is about 12695.9773156697. The cubic root of 161187840 is about 544.2236681175.

The spelling of 161187840 in words is "one hundred sixty-one million, one hundred eighty-seven thousand, eight hundred forty".