1778009436 has 144 divisors (see below), whose sum is σ = 5522549760. Its totient is φ = 470966400.

The previous prime is 1778009419. The next prime is 1778009437. The reversal of 1778009436 is 6349008771.

It is a super-2 number, since 2×1778009436² = 6322635109010076192, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1778009391 and 1778009400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1778009437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 221086 + ... + 228986.

It is an arithmetic number, because the mean of its divisors is an integer number (38351040).

Almost surely, 2^1778009436 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1778009436, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2761274880).

1778009436 is an abundant number, since it is smaller than the sum of its proper divisors (3744540324).

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

1778009436 is a wasteful number, since it uses less digits than its factorization.

1778009436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7984 (or 7979 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 45.

The square root of 1778009436 is about 42166.4491746697. The cubic root of 1778009436 is about 1211.4663451351.

The spelling of 1778009436 in words is "one billion, seven hundred seventy-eight million, nine thousand, four hundred thirty-six".