1155665620 has 24 divisors (see below), whose sum is σ = 2427957000. Its totient is φ = 462064512.

The previous prime is 1155665617. The next prime is 1155665639. The reversal of 1155665620 is 265665511.

It can be written as a sum of positive squares in 4 ways, for example, as 688327696 + 467337924 = 26236^2 + 21618^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1155665620.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39646 + ... + 62314.

It is an arithmetic number, because the mean of its divisors is an integer number (101164875).

Almost surely, 2^1155665620 is an apocalyptic number.

1155665620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1155665620 is an abundant number, since it is smaller than the sum of its proper divisors (1272291380).

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

1155665620 is a wasteful number, since it uses less digits than its factorization.

1155665620 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25227 (or 25225 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 37.

The square root of 1155665620 is about 33995.0822914139. The cubic root of 1155665620 is about 1049.4072603133.

The spelling of 1155665620 in words is "one billion, one hundred fifty-five million, six hundred sixty-five thousand, six hundred twenty".