161856780 has 48 divisors (see below), whose sum is σ = 458949120. Its totient is φ = 42614208.

The previous prime is 161856769. The next prime is 161856803. The reversal of 161856780 is 87658161.

161856780 is nontrivially palindromic in base 11.

161856780 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12334 + ... + 21813.

It is an arithmetic number, because the mean of its divisors is an integer number (9561440).

Almost surely, 2^161856780 is an apocalyptic number.

161856780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161856780 is an abundant number, since it is smaller than the sum of its proper divisors (297092340).

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

161856780 is a wasteful number, since it uses less digits than its factorization.

161856780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34238 (or 34236 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 42.

The square root of 161856780 is about 12722.2946043550. The cubic root of 161856780 is about 544.9754835646.

The spelling of 161856780 in words is "one hundred sixty-one million, eight hundred fifty-six thousand, seven hundred eighty".