1155990978 has 24 divisors (see below), whose sum is σ = 2528059248. Its totient is φ = 381728472.

The previous prime is 1155990977. The next prime is 1155991009. The reversal of 1155990978 is 8790995511.

1155990978 is a `hidden beast` number, since 11 + 559 + 9 + 0 + 9 + 78 = 666.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1155990977) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 298176 + ... + 302027.

It is an arithmetic number, because the mean of its divisors is an integer number (105335802).

Almost surely, 2^1155990978 is an apocalyptic number.

1155990978 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1155990978 is an abundant number, since it is smaller than the sum of its proper divisors (1372068270).

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

1155990978 is a wasteful number, since it uses less digits than its factorization.

1155990978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 600318 (or 600315 counting only the distinct ones).

The product of its (nonzero) digits is 1020600, while the sum is 54.

The square root of 1155990978 is about 33999.8673232705. The cubic root of 1155990978 is about 1049.5057319949.

The spelling of 1155990978 in words is "one billion, one hundred fifty-five million, nine hundred ninety thousand, nine hundred seventy-eight".