161973780 has 48 divisors (see below), whose sum is σ = 464595264. Its totient is φ = 42138880.

The previous prime is 161973769. The next prime is 161973809. The reversal of 161973780 is 87379161.

It is a congruent number.

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, 30462 + ... + 35381.

It is an arithmetic number, because the mean of its divisors is an integer number (9679068).

Almost surely, 2^161973780 is an apocalyptic number.

161973780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

161973780 is an abundant number, since it is smaller than the sum of its proper divisors (302621484).

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

161973780 is a wasteful number, since it uses less digits than its factorization.

161973780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65896 (or 65894 counting only the distinct ones).

The product of its (nonzero) digits is 63504, while the sum is 42.

The square root of 161973780 is about 12726.8920007989. The cubic root of 161973780 is about 545.1067658295.

The spelling of 161973780 in words is "one hundred sixty-one million, nine hundred seventy-three thousand, seven hundred eighty".