1191021040 has 40 divisors (see below), whose sum is σ = 3020864688. Its totient is φ = 433098240.

The previous prime is 1191020893. The next prime is 1191021043. The reversal of 1191021040 is 401201911.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×1191021040² = 2837062235445363200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1191020999 and 1191021017.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1191021043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 675837 + ... + 677596.

Almost surely, 2^1191021040 is an apocalyptic number.

1191021040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1191021040 is an abundant number, since it is smaller than the sum of its proper divisors (1829843648).

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

1191021040 is a wasteful number, since it uses less digits than its factorization.

1191021040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1353457 (or 1353451 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 19.

The square root of 1191021040 is about 34511.1726836397. The cubic root of 1191021040 is about 1060.0014951919.

Adding to 1191021040 its reverse (401201911), we get a palindrome (1592222951).

The spelling of 1191021040 in words is "one billion, one hundred ninety-one million, twenty-one thousand, forty".