161287440 has 160 divisors (see below), whose sum is σ = 527216256. Its totient is φ = 40734720.

The previous prime is 161287433. The next prime is 161287457. The reversal of 161287440 is 44782161.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 363859 + ... + 364301.

Almost surely, 2^161287440 is an apocalyptic number.

161287440 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 161287440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (263608128).

161287440 is an abundant number, since it is smaller than the sum of its proper divisors (365928816).

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

161287440 is a wasteful number, since it uses less digits than its factorization.

161287440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 537 (or 531 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 33.

The square root of 161287440 is about 12699.8992121985. The cubic root of 161287440 is about 544.3357392609.

The spelling of 161287440 in words is "one hundred sixty-one million, two hundred eighty-seven thousand, four hundred forty".