809978400144 has 135 divisors (see below), whose sum is σ = 2330885544897. Its totient is φ = 262566099072.

The previous prime is 809978400137. The next prime is 809978400149. The reversal of 809978400144 is 441004879908.

The square root of 809978400144 is 899988.

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

809978400144 is a `hidden beast` number, since 8 + 0 + 9 + 97 + 8 + 400 + 144 = 666.

809978400144 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in only one way, i.e., 724779795600 + 85198604544 = 851340^2 + 291888^2 .

It is not an unprimeable number, because it can be changed into a prime (809978400149) 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, 399593659 + ... + 399595685.

Almost surely, 2^809978400144 is an apocalyptic number.

809978400144 is the 899988-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 809978400144

809978400144 is an abundant number, since it is smaller than the sum of its proper divisors (1520907144753).

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

809978400144 is an equidigital number, since it uses as much as digits as its factorization.

809978400144 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4142 (or 2069 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 54.

The spelling of 809978400144 in words is "eight hundred nine billion, nine hundred seventy-eight million, four hundred thousand, one hundred forty-four".