16738216778 has 4 divisors (see below), whose sum is σ = 25107325170. Its totient is φ = 8369108388.

The previous prime is 16738216771. The next prime is 16738216799. The reversal of 16738216778 is 87761283761.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 16283546449 + 454670329 = 127607^2 + 21323^2 .

It is not an unprimeable number, because it can be changed into a prime (16738216771) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4184554193 + ... + 4184554196.

Almost surely, 2^16738216778 is an apocalyptic number.

16738216778 is a deficient number, since it is larger than the sum of its proper divisors (8369108392).

16738216778 is an equidigital number, since it uses as much as digits as its factorization.

16738216778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8369108391.

The product of its digits is 4741632, while the sum is 56.

The spelling of 16738216778 in words is "sixteen billion, seven hundred thirty-eight million, two hundred sixteen thousand, seven hundred seventy-eight".