1851139980 has 144 divisors (see below), whose sum is σ = 6129876480. Its totient is φ = 467633088.

The previous prime is 1851139951. The next prime is 1851139987. The reversal of 1851139980 is 899311581.

1851139980 is a `hidden beast` number, since 18 + 511 + 39 + 98 + 0 = 666.

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 (1851139987) 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, 82317 + ... + 102363.

Almost surely, 2^1851139980 is an apocalyptic number.

1851139980 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 1851139980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3064938240).

1851139980 is an abundant number, since it is smaller than the sum of its proper divisors (4278736500).

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

1851139980 is a wasteful number, since it uses less digits than its factorization.

1851139980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20090 (or 20076 counting only the distinct ones).

The product of its (nonzero) digits is 77760, while the sum is 45.

The square root of 1851139980 is about 43024.8762926751. The cubic root of 1851139980 is about 1227.8531258802.

The spelling of 1851139980 in words is "one billion, eight hundred fifty-one million, one hundred thirty-nine thousand, nine hundred eighty".