91211221001 has 8 divisors (see below), whose sum is σ = 96163982400. Its totient is φ = 86273676720.

The previous prime is 91211220983. The next prime is 91211221063. The reversal of 91211221001 is 10012211219.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-91211221001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91211221081) 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, 3791966 + ... + 3815943.

It is an arithmetic number, because the mean of its divisors is an integer number (12020497800).

Almost surely, 2^91211221001 is an apocalyptic number.

It is an amenable number.

91211221001 is a deficient number, since it is larger than the sum of its proper divisors (4952761399).

91211221001 is a wasteful number, since it uses less digits than its factorization.

91211221001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7608559.

The product of its (nonzero) digits is 72, while the sum is 20.

The spelling of 91211221001 in words is "ninety-one billion, two hundred eleven million, two hundred twenty-one thousand, one".