1081475991 has 24 divisors (see below), whose sum is σ = 1646190000. Its totient is φ = 682273152.

The previous prime is 1081475987. The next prime is 1081475999. The reversal of 1081475991 is 1995741801.

It is a happy number.

1081475991 is a `hidden beast` number, since 10 + 8 + 1 + 47 + 599 + 1 = 666.

It is not a de Polignac number, because 1081475991 - 2² = 1081475987 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1081475999) 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 23 ways as a sum of consecutive naturals, for example, 176365 + ... + 182393.

It is an arithmetic number, because the mean of its divisors is an integer number (68591250).

Almost surely, 2^1081475991 is an apocalyptic number.

1081475991 is a deficient number, since it is larger than the sum of its proper divisors (564714009).

1081475991 is a wasteful number, since it uses less digits than its factorization.

1081475991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7103 (or 7100 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 45.

The square root of 1081475991 is about 32885.8022708889. The cubic root of 1081475991 is about 1026.4527458219.

The spelling of 1081475991 in words is "one billion, eighty-one million, four hundred seventy-five thousand, nine hundred ninety-one".