91001001001 has 4 divisors (see below), whose sum is σ = 91002610000. Its totient is φ = 90999392004.

The previous prime is 91001000999. The next prime is 91001001019. The reversal of 91001001001 is 10010010019.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 91001001001 - 2¹ = 91001000999 is a prime.

It is a Duffinian number.

91001001001 is a modest number, since divided by 1001001 gives 91 as remainder.

It is not an unprimeable number, because it can be changed into a prime (91001001041) 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 3 ways as a sum of consecutive naturals, for example, 716451 + ... + 833848.

It is an arithmetic number, because the mean of its divisors is an integer number (22750652500).

Almost surely, 2^91001001001 is an apocalyptic number.

It is an amenable number.

91001001001 is a deficient number, since it is larger than the sum of its proper divisors (1608999).

91001001001 is a wasteful number, since it uses less digits than its factorization.

91001001001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1608998.

The product of its (nonzero) digits is 9, while the sum is 13.

It can be divided in two parts, 9100 and 1001001, that added together give a palindrome (1010101).

The spelling of 91001001001 in words is "ninety-one billion, one million, one thousand, one".