1205505840 has 240 divisors, whose sum is σ = 4742910720. Its totient is φ = 250467840.

The previous prime is 1205505839. The next prime is 1205505841. The reversal of 1205505840 is 485055021.

It is an interprime number because it is at equal distance from previous prime (1205505839) and next prime (1205505841).

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 (30).

It is a junction number, because it is equal to n+sod(n) for n = 1205505798 and 1205505807.

It is not an unprimeable number, because it can be changed into a prime (1205505841) 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, 124701 + ... + 134019.

It is an arithmetic number, because the mean of its divisors is an integer number (19762128).

Almost surely, 2^1205505840 is an apocalyptic number.

1205505840 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 1205505840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2371455360).

1205505840 is an abundant number, since it is smaller than the sum of its proper divisors (3537404880).

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

1205505840 is a wasteful number, since it uses less digits than its factorization.

1205505840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9360 (or 9347 counting only the distinct ones).

The product of its (nonzero) digits is 8000, while the sum is 30.

The square root of 1205505840 is about 34720.3951590416. The cubic root of 1205505840 is about 1064.2813198881.

The spelling of 1205505840 in words is "one billion, two hundred five million, five hundred five thousand, eight hundred forty".