1808736840 has 48 divisors (see below), whose sum is σ = 5878395900. Its totient is φ = 482329728.

The previous prime is 1808736793. The next prime is 1808736847. The reversal of 1808736840 is 486378081.

It can be written as a sum of positive squares in 2 ways, for example, as 1683789156 + 124947684 = 41034^2 + 11178^2 .

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is not an unprimeable number, because it can be changed into a prime (1808736847) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2511775 + ... + 2512494.

Almost surely, 2^1808736840 is an apocalyptic number.

1808736840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1808736840 is an abundant number, since it is smaller than the sum of its proper divisors (4069659060).

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

1808736840 is a wasteful number, since it uses less digits than its factorization.

1808736840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5024286 (or 5024279 counting only the distinct ones).

The product of its (nonzero) digits is 258048, while the sum is 45.

The square root of 1808736840 is about 42529.2468778839. The cubic root of 1808736840 is about 1218.4053428572.

The spelling of 1808736840 in words is "one billion, eight hundred eight million, seven hundred thirty-six thousand, eight hundred forty".