1000090991 has 8 divisors (see below), whose sum is σ = 1053908064. Its totient is φ = 947135200.

The previous prime is 1000090979. The next prime is 1000091003. The reversal of 1000090991 is 1990900001.

It is an interprime number because it is at equal distance from previous prime (1000090979) and next prime (1000091003).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1000090991 - 2¹⁰ = 1000089967 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1000090951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 212936 + ... + 217581.

It is an arithmetic number, because the mean of its divisors is an integer number (131738508).

Almost surely, 2^1000090991 is an apocalyptic number.

1000090991 is a deficient number, since it is larger than the sum of its proper divisors (53817073).

1000090991 is a wasteful number, since it uses less digits than its factorization.

1000090991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 430641.

The product of its (nonzero) digits is 729, while the sum is 29.

The square root of 1000090991 is about 31624.2152629911. The cubic root of 1000090991 is about 1000.0303294135.

Adding to 1000090991 its reverse (1990900001), we get a palindrome (2990990992).

The spelling of 1000090991 in words is "one billion, ninety thousand, nine hundred ninety-one".