1865561040 has 240 divisors, whose sum is σ = 7242393600. Its totient is φ = 421521408.

The previous prime is 1865561021. The next prime is 1865561057. The reversal of 1865561040 is 401655681.

It is a tau number, because it is divible by the number of its divisors (240).

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

It is a junction number, because it is equal to n+sod(n) for n = 1865560986 and 1865561004.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 446481 + ... + 450639.

It is an arithmetic number, because the mean of its divisors is an integer number (30176640).

Almost surely, 2^1865561040 is an apocalyptic number.

1865561040 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 1865561040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3621196800).

1865561040 is an abundant number, since it is smaller than the sum of its proper divisors (5376832560).

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

1865561040 is a wasteful number, since it uses less digits than its factorization.

1865561040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4274 (or 4265 counting only the distinct ones).

The product of its (nonzero) digits is 28800, while the sum is 36.

The square root of 1865561040 is about 43192.1409517982. The cubic root of 1865561040 is about 1231.0333572640.

The spelling of 1865561040 in words is "one billion, eight hundred sixty-five million, five hundred sixty-one thousand, forty".