1851085840 has 40 divisors (see below), whose sum is σ = 4319823960. Its totient is φ = 737673216.

The previous prime is 1851085777. The next prime is 1851085843. The reversal of 1851085840 is 485801581.

It can be written as a sum of positive squares in 4 ways, for example, as 47554816 + 1803531024 = 6896^2 + 42468^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a junction number, because it is equal to n+sod(n) for n = 1851085793 and 1851085802.

It is not an unprimeable number, because it can be changed into a prime (1851085843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 21489 + ... + 64528.

It is an arithmetic number, because the mean of its divisors is an integer number (107995599).

Almost surely, 2^1851085840 is an apocalyptic number.

1851085840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1851085840 is an abundant number, since it is smaller than the sum of its proper divisors (2468738120).

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

1851085840 is a wasteful number, since it uses less digits than its factorization.

1851085840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86299 (or 86293 counting only the distinct ones).

The product of its (nonzero) digits is 51200, while the sum is 40.

The square root of 1851085840 is about 43024.2471171780. The cubic root of 1851085840 is about 1227.8411554877.

The spelling of 1851085840 in words is "one billion, eight hundred fifty-one million, eighty-five thousand, eight hundred forty".