1171821540 has 24 divisors (see below), whose sum is σ = 3281100480. Its totient is φ = 312485728.

The previous prime is 1171821527. The next prime is 1171821551. The reversal of 1171821540 is 451281711.

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

It is a junction number, because it is equal to n+sod(n) for n = 1171821498 and 1171821507.

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, 9765120 + ... + 9765239.

It is an arithmetic number, because the mean of its divisors is an integer number (136712520).

Almost surely, 2^1171821540 is an apocalyptic number.

1171821540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1171821540 is an abundant number, since it is smaller than the sum of its proper divisors (2109278940).

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

1171821540 is a wasteful number, since it uses less digits than its factorization.

1171821540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19530371 (or 19530369 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 30.

The square root of 1171821540 is about 34231.8790018895. The cubic root of 1171821540 is about 1054.2747994153.

The spelling of 1171821540 in words is "one billion, one hundred seventy-one million, eight hundred twenty-one thousand, five hundred forty".