161819745 has 16 divisors (see below), whose sum is σ = 259074240. Its totient is φ = 86249664.

The previous prime is 161819741. The next prime is 161819761. The reversal of 161819745 is 547918161.

It is not a de Polignac number, because 161819745 - 2² = 161819741 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 161819697 and 161819706.

It is not an unprimeable number, because it can be changed into a prime (161819741) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 36246 + ... + 40464.

It is an arithmetic number, because the mean of its divisors is an integer number (16192140).

Almost surely, 2^161819745 is an apocalyptic number.

161819745 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

161819745 is a deficient number, since it is larger than the sum of its proper divisors (97254495).

161819745 is a wasteful number, since it uses less digits than its factorization.

161819745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6784.

The product of its digits is 60480, while the sum is 42.

The square root of 161819745 is about 12720.8390053487. The cubic root of 161819745 is about 544.9339144963.

The spelling of 161819745 in words is "one hundred sixty-one million, eight hundred nineteen thousand, seven hundred forty-five".