1786978040400 has 540 divisors, whose sum is σ = 7349916290652. Its totient is φ = 400743383040.

The previous prime is 1786978040381. The next prime is 1786978040401. The reversal of 1786978040400 is 40408796871.

It is a happy number.

1786978040400 is a `hidden beast` number, since 1 + 78 + 6 + 97 + 80 + 4 + 0 + 400 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 31533235776 + 1755444804624 = 177576^2 + 1324932^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1786978040401) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 9253632 + ... + 9444768.

Almost surely, 2^{1786978040400} is an apocalyptic number.

1786978040400 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1786978040400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3674958145326).

1786978040400 is an abundant number, since it is smaller than the sum of its proper divisors (5562938250252).

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

1786978040400 is a wasteful number, since it uses less digits than its factorization.

1786978040400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191228 (or 191207 counting only the distinct ones).

The product of its (nonzero) digits is 2709504, while the sum is 54.

The spelling of 1786978040400 in words is "one trillion, seven hundred eighty-six billion, nine hundred seventy-eight million, forty thousand, four hundred".