1778421840 has 160 divisors (see below), whose sum is σ = 5953118976. Its totient is φ = 436592640.

The previous prime is 1778421791. The next prime is 1778421871. The reversal of 1778421840 is 481248771.

It is a junction number, because it is equal to n+sod(n) for n = 1778421792 and 1778421801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2018200 + ... + 2019080.

Almost surely, 2^1778421840 is an apocalyptic number.

1778421840 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 1778421840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2976559488).

1778421840 is an abundant number, since it is smaller than the sum of its proper divisors (4174697136).

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

1778421840 is a wasteful number, since it uses less digits than its factorization.

1778421840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1557 (or 1551 counting only the distinct ones).

The product of its (nonzero) digits is 100352, while the sum is 42.

The square root of 1778421840 is about 42171.3390823673. The cubic root of 1778421840 is about 1211.5600032327.

The spelling of 1778421840 in words is "one billion, seven hundred seventy-eight million, four hundred twenty-one thousand, eight hundred forty".