161553940 has 48 divisors (see below), whose sum is σ = 349300224. Its totient is φ = 62726400.

The previous prime is 161553929. The next prime is 161553943. The reversal of 161553940 is 49355161.

It is a junction number, because it is equal to n+sod(n) for n = 161553896 and 161553905.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (161553943) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 221857 + ... + 222583.

It is an arithmetic number, because the mean of its divisors is an integer number (7277088).

Almost surely, 2^161553940 is an apocalyptic number.

161553940 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 161553940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (174650112).

161553940 is an abundant number, since it is smaller than the sum of its proper divisors (187746284).

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

161553940 is a wasteful number, since it uses less digits than its factorization.

161553940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1048 (or 1046 counting only the distinct ones).

The product of its (nonzero) digits is 16200, while the sum is 34.

The square root of 161553940 is about 12710.3870908796. The cubic root of 161553940 is about 544.6353816243.

It can be divided in two parts, 1615 and 53940, that added together give a palindrome (55555).

The spelling of 161553940 in words is "one hundred sixty-one million, five hundred fifty-three thousand, nine hundred forty".