1865449980 has 192 divisors, whose sum is σ = 6007478400. Its totient is φ = 480245760.

The previous prime is 1865449931. The next prime is 1865449997. The reversal of 1865449980 is 899445681.

1865449980 is a `hidden beast` number, since 1 + 8 + 6 + 544 + 9 + 98 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 2412874 + ... + 2413646.

It is an arithmetic number, because the mean of its divisors is an integer number (31288950).

Almost surely, 2^1865449980 is an apocalyptic number.

1865449980 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 1865449980, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3003739200).

1865449980 is an abundant number, since it is smaller than the sum of its proper divisors (4142028420).

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

1865449980 is a wasteful number, since it uses less digits than its factorization.

1865449980 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 941 (or 933 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 54.

The square root of 1865449980 is about 43190.8552821080. The cubic root of 1865449980 is about 1231.0089282808.

The spelling of 1865449980 in words is "one billion, eight hundred sixty-five million, four hundred forty-nine thousand, nine hundred eighty".