161778610 has 16 divisors (see below), whose sum is σ = 332801856. Its totient is φ = 55466928.

The previous prime is 161778557. The next prime is 161778611. The reversal of 161778610 is 16877161.

It is a self number, because there is not a number n which added to its sum of digits gives 161778610.

It is not an unprimeable number, because it can be changed into a prime (161778611) by changing a digit.

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, 1155492 + ... + 1155631.

It is an arithmetic number, because the mean of its divisors is an integer number (20800116).

Almost surely, 2^161778610 is an apocalyptic number.

161778610 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

161778610 is an abundant number, since it is smaller than the sum of its proper divisors (171023246).

161778610 is a wasteful number, since it uses less digits than its factorization.

161778610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2311137.

The product of its (nonzero) digits is 14112, while the sum is 37.

The square root of 161778610 is about 12719.2220674065. Note that the first 3 decimals coincide. The cubic root of 161778610 is about 544.8877360438.

The spelling of 161778610 in words is "one hundred sixty-one million, seven hundred seventy-eight thousand, six hundred ten".