16423108778 has 4 divisors (see below), whose sum is σ = 24634663170. Its totient is φ = 8211554388.

The previous prime is 16423108771. The next prime is 16423108799. The reversal of 16423108778 is 87780132461.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 87780132461 = 7 ⋅12540018923.

It can be written as a sum of positive squares in only one way, i.e., 13045523089 + 3377585689 = 114217^2 + 58117^2 .

It is not an unprimeable number, because it can be changed into a prime (16423108771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4105777193 + ... + 4105777196.

Almost surely, 2^16423108778 is an apocalyptic number.

16423108778 is a deficient number, since it is larger than the sum of its proper divisors (8211554392).

16423108778 is an equidigital number, since it uses as much as digits as its factorization.

16423108778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8211554391.

The product of its (nonzero) digits is 451584, while the sum is 47.

The spelling of 16423108778 in words is "sixteen billion, four hundred twenty-three million, one hundred eight thousand, seven hundred seventy-eight".