161987040 has 240 divisors, whose sum is σ = 592764480. Its totient is φ = 41610240.

The previous prime is 161987029. The next prime is 161987041. The reversal of 161987040 is 40789161.

It is a tau number, because it is divible by the number of its divisors (240).

It is a super-2 number, since 2×161987040² = 52479602255923200, which contains 22 as substring.

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 = 161986986 and 161987004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161987041) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 375625 + ... + 376055.

It is an arithmetic number, because the mean of its divisors is an integer number (2469852).

Almost surely, 2^161987040 is an apocalyptic number.

161987040 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 161987040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (296382240).

161987040 is an abundant number, since it is smaller than the sum of its proper divisors (430777440).

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

161987040 is a wasteful number, since it uses less digits than its factorization.

161987040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 487 (or 470 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 36.

The square root of 161987040 is about 12727.4129342927. The cubic root of 161987040 is about 545.1216404972.

The spelling of 161987040 in words is "one hundred sixty-one million, nine hundred eighty-seven thousand, forty".