1780336840 has 16 divisors (see below), whose sum is σ = 4005757980. Its totient is φ = 712134720.

The previous prime is 1780336823. The next prime is 1780336847. The reversal of 1780336840 is 486330871.

It can be written as a sum of positive squares in 2 ways, for example, as 1707507684 + 72829156 = 41322^2 + 8534^2 .

It is a super-2 number, since 2×1780336840² = 6339198527722371200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40), and also a Moran number because the ratio is a prime number: 44508421 = 1780336840 / (1 + 7 + 8 + 0 + 3 + 3 + 6 + 8 + 4 + 0).

It is a junction number, because it is equal to n+sod(n) for n = 1780336793 and 1780336802.

It is not an unprimeable number, because it can be changed into a prime (1780336847) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22254171 + ... + 22254250.

Almost surely, 2^1780336840 is an apocalyptic number.

1780336840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1780336840 is an abundant number, since it is smaller than the sum of its proper divisors (2225421140).

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

1780336840 is a wasteful number, since it uses less digits than its factorization.

1780336840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44508432 (or 44508428 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 40.

The square root of 1780336840 is about 42194.0379674664. The cubic root of 1780336840 is about 1211.9947154551.

The spelling of 1780336840 in words is "one billion, seven hundred eighty million, three hundred thirty-six thousand, eight hundred forty".