161401440 has 48 divisors (see below), whose sum is σ = 508416048. Its totient is φ = 43040256.

The previous prime is 161401439. The next prime is 161401441. The reversal of 161401440 is 44104161.

It is an interprime number because it is at equal distance from previous prime (161401439) and next prime (161401441).

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161401441) 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 7 ways as a sum of consecutive naturals, for example, 167647 + ... + 168606.

It is an arithmetic number, because the mean of its divisors is an integer number (10592001).

Almost surely, 2^161401440 is an apocalyptic number.

161401440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161401440 is an abundant number, since it is smaller than the sum of its proper divisors (347014608).

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

161401440 is a wasteful number, since it uses less digits than its factorization.

161401440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336271 (or 336263 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 161401440 is about 12704.3866439903. The cubic root of 161401440 is about 544.4639568492.

The spelling of 161401440 in words is "one hundred sixty-one million, four hundred one thousand, four hundred forty".