1181399780 has 24 divisors (see below), whose sum is σ = 2706480000. Its totient is φ = 429599840.

The previous prime is 1181399777. The next prime is 1181399797. The reversal of 1181399780 is 879931811.

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, 2684780 + ... + 2685219.

It is an arithmetic number, because the mean of its divisors is an integer number (112770000).

Almost surely, 2^1181399780 is an apocalyptic number.

1181399780 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1181399780 is an abundant number, since it is smaller than the sum of its proper divisors (1525080220).

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

1181399780 is a wasteful number, since it uses less digits than its factorization.

1181399780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5370019 (or 5370017 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 47.

The square root of 1181399780 is about 34371.4966214740. The cubic root of 1181399780 is about 1057.1394870497.

The spelling of 1181399780 in words is "one billion, one hundred eighty-one million, three hundred ninety-nine thousand, seven hundred eighty".