1181281640 has 64 divisors (see below), whose sum is σ = 3313733760. Its totient is φ = 368190720.

The previous prime is 1181281609. The next prime is 1181281643. The reversal of 1181281640 is 461821811.

It is a happy number.

It is a super-3 number, since 3×1181281640³ (a number of 28 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1181281597 and 1181281606.

It is not an unprimeable number, because it can be changed into a prime (1181281643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 188687 + ... + 194846.

It is an arithmetic number, because the mean of its divisors is an integer number (51777090).

Almost surely, 2^1181281640 is an apocalyptic number.

1181281640 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1181281640 is an abundant number, since it is smaller than the sum of its proper divisors (2132452120).

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

1181281640 is a wasteful number, since it uses less digits than its factorization.

1181281640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 383562 (or 383558 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 32.

The square root of 1181281640 is about 34369.7780033564. The cubic root of 1181281640 is about 1057.1042478855.

The spelling of 1181281640 in words is "one billion, one hundred eighty-one million, two hundred eighty-one thousand, six hundred forty".