18978919696 has 135 divisors (see below), whose sum is σ = 42181914117. Its totient is φ = 8265840000.

The previous prime is 18978919651. The next prime is 18978919699. The reversal of 18978919696 is 69691987981.

The square root of 18978919696 is 137764.

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

It can be written as a sum of positive squares in only one way, i.e., 18234721296 + 744198400 = 135036^2 + 27280^2 .

It is not an unprimeable number, because it can be changed into a prime (18978919699) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 187910046 + ... + 187910146.

Almost surely, 2^18978919696 is an apocalyptic number.

18978919696 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

18978919696 is the 137764-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18978919696

18978919696 is an abundant number, since it is smaller than the sum of its proper divisors (23202994421).

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

18978919696 is a wasteful number, since it uses less digits than its factorization.

18978919696 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294 (or 145 counting only the distinct ones).

The product of its digits is 105815808, while the sum is 73.

The spelling of 18978919696 in words is "eighteen billion, nine hundred seventy-eight million, nine hundred nineteen thousand, six hundred ninety-six".