1851540372 has 144 divisors (see below), whose sum is σ = 5315611392. Its totient is φ = 538487040.

The previous prime is 1851540371. The next prime is 1851540373. The reversal of 1851540372 is 2730451581.

1851540372 is a `hidden beast` number, since 1 + 85 + 1 + 540 + 37 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (1851540371) and next prime (1851540373).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1851540371) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 985498 + ... + 987374.

It is an arithmetic number, because the mean of its divisors is an integer number (36913968).

Almost surely, 2^1851540372 is an apocalyptic number.

1851540372 is a gapful number since it is divisible by the number (12) 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 1851540372, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2657805696).

1851540372 is an abundant number, since it is smaller than the sum of its proper divisors (3464071020).

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

1851540372 is a wasteful number, since it uses less digits than its factorization.

1851540372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1998 (or 1993 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The square root of 1851540372 is about 43029.5290701630. The cubic root of 1851540372 is about 1227.9416455911.

The spelling of 1851540372 in words is "one billion, eight hundred fifty-one million, five hundred forty thousand, three hundred seventy-two".