13781820816 has 105 divisors (see below), whose sum is σ = 40071967131. Its totient is φ = 4589714016.

The previous prime is 13781820803. The next prime is 13781820821. The reversal of 13781820816 is 61802818731.

It is a happy number.

The square root of 13781820816 is 117396.

It is a perfect power (a square), and thus also a powerful number.

It is an unprimeable number.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 12678225 + ... + 12679311.

Almost surely, 2^13781820816 is an apocalyptic number.

13781820816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

13781820816 is the 117396-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 13781820816

13781820816 is an abundant number, since it is smaller than the sum of its proper divisors (26290146315).

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

13781820816 is an frugal number, since it uses more digits than its factorization.

13781820816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2200 (or 1092 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 45.

The spelling of 13781820816 in words is "thirteen billion, seven hundred eighty-one million, eight hundred twenty thousand, eight hundred sixteen".