16781391488 has 32 divisors (see below), whose sum is σ = 34584502500. Its totient is φ = 8101359616.

The previous prime is 16781391461. The next prime is 16781391521. The reversal of 16781391488 is 88419318761.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 16177804864 + 603586624 = 127192^2 + 24568^2 .

It is a tau number, because it is divible by the number of its divisors (32).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2256713 + ... + 2264136.

Almost surely, 2^16781391488 is an apocalyptic number.

It is an amenable number.

16781391488 is an abundant number, since it is smaller than the sum of its proper divisors (17803111012).

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

16781391488 is an equidigital number, since it uses as much as digits as its factorization.

16781391488 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4520892 (or 4520880 counting only the distinct ones).

The product of its digits is 2322432, while the sum is 56.

The spelling of 16781391488 in words is "sixteen billion, seven hundred eighty-one million, three hundred ninety-one thousand, four hundred eighty-eight".