1006105991 has 8 divisors (see below), whose sum is σ = 1103088000. Its totient is φ = 910043640.

The previous prime is 1006105987. The next prime is 1006106021. The reversal of 1006105991 is 1995016001.

It is a happy number.

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

It is not a de Polignac number, because 1006105991 - 2² = 1006105987 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 (1006105901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 227621 + ... + 231998.

It is an arithmetic number, because the mean of its divisors is an integer number (137886000).

Almost surely, 2^1006105991 is an apocalyptic number.

1006105991 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1006105991 is a deficient number, since it is larger than the sum of its proper divisors (96982009).

1006105991 is a wasteful number, since it uses less digits than its factorization.

1006105991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 459829.

The product of its (nonzero) digits is 2430, while the sum is 32.

The square root of 1006105991 is about 31719.1738700742. The cubic root of 1006105991 is about 1002.0312017593.

It can be divided in two parts, 100610 and 5991, that added together give a palindrome (106601).

The spelling of 1006105991 in words is "one billion, six million, one hundred five thousand, nine hundred ninety-one".