1156561320 has 32 divisors (see below), whose sum is σ = 3469684320. Its totient is φ = 308416320.

The previous prime is 1156561309. The next prime is 1156561321. The reversal of 1156561320 is 231656511.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is not an unprimeable number, because it can be changed into a prime (1156561321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4818886 + ... + 4819125.

It is an arithmetic number, because the mean of its divisors is an integer number (108427635).

Almost surely, 2^1156561320 is an apocalyptic number.

1156561320 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1156561320 is an abundant number, since it is smaller than the sum of its proper divisors (2313123000).

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

1156561320 is a wasteful number, since it uses less digits than its factorization.

1156561320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9638025 (or 9638021 counting only the distinct ones).

The product of its (nonzero) digits is 5400, while the sum is 30.

The square root of 1156561320 is about 34008.2537040643. The cubic root of 1156561320 is about 1049.6783050785.

The spelling of 1156561320 in words is "one billion, one hundred fifty-six million, five hundred sixty-one thousand, three hundred twenty".