1191905140 has 12 divisors (see below), whose sum is σ = 2503000836. Its totient is φ = 476762048.

The previous prime is 1191905111. The next prime is 1191905147. The reversal of 1191905140 is 415091911.

It can be written as a sum of positive squares in 2 ways, for example, as 311240164 + 880664976 = 17642^2 + 29676^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1191905147) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29797609 + ... + 29797648.

It is an arithmetic number, because the mean of its divisors is an integer number (208583403).

Almost surely, 2^1191905140 is an apocalyptic number.

1191905140 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1191905140 is an abundant number, since it is smaller than the sum of its proper divisors (1311095696).

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

1191905140 is a wasteful number, since it uses less digits than its factorization.

1191905140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 59595266 (or 59595264 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 31.

The square root of 1191905140 is about 34523.9792028671. The cubic root of 1191905140 is about 1060.2637115321.

The spelling of 1191905140 in words is "one billion, one hundred ninety-one million, nine hundred five thousand, one hundred forty".