1191878928 has 80 divisors (see below), whose sum is σ = 3513644160. Its totient is φ = 386550144.

The previous prime is 1191878927. The next prime is 1191878953. The reversal of 1191878928 is 8298781911.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (1191878927) 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, 21300 + ... + 53267.

It is an arithmetic number, because the mean of its divisors is an integer number (43920552).

Almost surely, 2^1191878928 is an apocalyptic number.

1191878928 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

1191878928 is an abundant number, since it is smaller than the sum of its proper divisors (2321765232).

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

1191878928 is a wasteful number, since it uses less digits than its factorization.

1191878928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74621 (or 74609 counting only the distinct ones).

The product of its digits is 580608, while the sum is 54.

The square root of 1191878928 is about 34523.5995805768. The cubic root of 1191878928 is about 1060.2559391473.

The spelling of 1191878928 in words is "one billion, one hundred ninety-one million, eight hundred seventy-eight thousand, nine hundred twenty-eight".