161740820 has 24 divisors (see below), whose sum is σ = 341560800. Its totient is φ = 64333472.

The previous prime is 161740793. The next prime is 161740847. The reversal of 161740820 is 28047161.

It is an interprime number because it is at equal distance from previous prime (161740793) and next prime (161740847).

It is a congruent number.

It is an unprimeable number.

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, 19010 + ... + 26169.

It is an arithmetic number, because the mean of its divisors is an integer number (14231700).

Almost surely, 2^161740820 is an apocalyptic number.

161740820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161740820 is an abundant number, since it is smaller than the sum of its proper divisors (179819980).

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

161740820 is a wasteful number, since it uses less digits than its factorization.

161740820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 45367 (or 45365 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 29.

The square root of 161740820 is about 12717.7364338156. The cubic root of 161740820 is about 544.8453058134.

Adding to 161740820 its reverse (28047161), we get a palindrome (189787981).

The spelling of 161740820 in words is "one hundred sixty-one million, seven hundred forty thousand, eight hundred twenty".