1165021020 has 72 divisors (see below), whose sum is σ = 3536909376. Its totient is φ = 310407552.

The previous prime is 1165021019. The next prime is 1165021051. The reversal of 1165021020 is 201205611.

1165021020 is a `hidden beast` number, since 1 + 1 + 650 + 2 + 10 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 1165020984 and 1165021002.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 302829 + ... + 306651.

Almost surely, 2^1165021020 is an apocalyptic number.

1165021020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1165021020 is an abundant number, since it is smaller than the sum of its proper divisors (2371888356).

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

1165021020 is a wasteful number, since it uses less digits than its factorization.

1165021020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5531 (or 5526 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 1165021020 is about 34132.4042516785. The cubic root of 1165021020 is about 1052.2313906911.

Adding to 1165021020 its reverse (201205611), we get a palindrome (1366226631).

The spelling of 1165021020 in words is "one billion, one hundred sixty-five million, twenty-one thousand, twenty".