1189906380 has 144 divisors (see below), whose sum is σ = 4056212160. Its totient is φ = 280152576.

The previous prime is 1189906271. The next prime is 1189906391. The reversal of 1189906380 is 836099811.

1189906380 is a `hidden beast` number, since 1 + 1 + 8 + 9 + 9 + 0 + 638 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 42766 + ... + 64874.

It is an arithmetic number, because the mean of its divisors is an integer number (28168140).

Almost surely, 2^1189906380 is an apocalyptic number.

1189906380 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1189906380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2028106080).

1189906380 is an abundant number, since it is smaller than the sum of its proper divisors (2866305780).

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

1189906380 is a wasteful number, since it uses less digits than its factorization.

1189906380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22160 (or 22155 counting only the distinct ones).

The product of its (nonzero) digits is 93312, while the sum is 45.

The square root of 1189906380 is about 34495.0196405220. The cubic root of 1189906380 is about 1059.6707117675.

The spelling of 1189906380 in words is "one billion, one hundred eighty-nine million, nine hundred six thousand, three hundred eighty".