1155120020 has 24 divisors (see below), whose sum is σ = 2491314504. Its totient is φ = 449559936.

The previous prime is 1155120017. The next prime is 1155120023. The reversal of 1155120020 is 200215511.

It is an interprime number because it is at equal distance from previous prime (1155120017) and next prime (1155120023).

It can be written as a sum of positive squares in 4 ways, for example, as 424607236 + 730512784 = 20606^2 + 27028^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1155120023) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 779747 + ... + 781226.

It is an arithmetic number, because the mean of its divisors is an integer number (103804771).

Almost surely, 2^1155120020 is an apocalyptic number.

1155120020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1155120020 is an abundant number, since it is smaller than the sum of its proper divisors (1336194484).

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

1155120020 is a wasteful number, since it uses less digits than its factorization.

1155120020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1561019 (or 1561017 counting only the distinct ones).

The product of its (nonzero) digits is 100, while the sum is 17.

The square root of 1155120020 is about 33987.0566539676. The cubic root of 1155120020 is about 1049.2420894894.

Adding to 1155120020 its reverse (200215511), we get a palindrome (1355335531).

The spelling of 1155120020 in words is "one billion, one hundred fifty-five million, one hundred twenty thousand, twenty".