1815806565552 has 240 divisors, whose sum is σ = 5877462687360. Its totient is φ = 480065854464.

The previous prime is 1815806565539. The next prime is 1815806565619. The reversal of 1815806565552 is 2555656085181.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a junction number, because it is equal to n+sod(n) for n = 1815806565492 and 1815806565501.

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, 1449108 + ... + 2394060.

It is an arithmetic number, because the mean of its divisors is an integer number (24489427864).

Almost surely, 2^{1815806565552} is an apocalyptic number.

1815806565552 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 1815806565552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2938731343680).

1815806565552 is an abundant number, since it is smaller than the sum of its proper divisors (4061656121808).

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

1815806565552 is a wasteful number, since it uses less digits than its factorization.

1815806565552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 945040 (or 945027 counting only the distinct ones).

The product of its (nonzero) digits is 14400000, while the sum is 57.

The spelling of 1815806565552 in words is "one trillion, eight hundred fifteen billion, eight hundred six million, five hundred sixty-five thousand, five hundred fifty-two".