1161273520 has 80 divisors (see below), whose sum is σ = 2956453632. Its totient is φ = 420698880.

The previous prime is 1161273517. The next prime is 1161273539. The reversal of 1161273520 is 253721611.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

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 15 ways as a sum of consecutive naturals, for example, 246709 + ... + 251371.

Almost surely, 2^1161273520 is an apocalyptic number.

1161273520 is a gapful number since it is divisible by the number (10) 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 1161273520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1478226816).

1161273520 is an abundant number, since it is smaller than the sum of its proper divisors (1795180112).

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

1161273520 is a wasteful number, since it uses less digits than its factorization.

1161273520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4970 (or 4964 counting only the distinct ones).

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 1161273520 is about 34077.4635206319. The cubic root of 1161273520 is about 1051.1019481932.

The spelling of 1161273520 in words is "one billion, one hundred sixty-one million, two hundred seventy-three thousand, five hundred twenty".