1161256220 has 24 divisors (see below), whose sum is σ = 2439611664. Its totient is φ = 464317056.

The previous prime is 1161256183. The next prime is 1161256241. The reversal of 1161256220 is 226521611.

It is a self number, because there is not a number n which added to its sum of digits gives 1161256220.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46979 + ... + 67301.

It is an arithmetic number, because the mean of its divisors is an integer number (101650486).

Almost surely, 2^1161256220 is an apocalyptic number.

1161256220 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1161256220 is an abundant number, since it is smaller than the sum of its proper divisors (1278355444).

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

1161256220 is a wasteful number, since it uses less digits than its factorization.

1161256220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23189 (or 23187 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 1161256220 is about 34077.2096862405. The cubic root of 1161256220 is about 1051.0967285920.

Adding to 1161256220 its reverse (226521611), we get a palindrome (1387777831).

The spelling of 1161256220 in words is "one billion, one hundred sixty-one million, two hundred fifty-six thousand, two hundred twenty".