9912001221 has 24 divisors (see below), whose sum is σ = 14827947264. Its totient is φ = 6376295520.

The previous prime is 9912001217. The next prime is 9912001241. The reversal of 9912001221 is 1221002199.

It is not a de Polignac number, because 9912001221 - 2² = 9912001217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9912001241) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 134986 + ... + 195051.

It is an arithmetic number, because the mean of its divisors is an integer number (617831136).

Almost surely, 2^9912001221 is an apocalyptic number.

It is an amenable number.

9912001221 is a deficient number, since it is larger than the sum of its proper divisors (4915946043).

9912001221 is a wasteful number, since it uses less digits than its factorization.

9912001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 330161 (or 330158 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 9912001221 is about 99559.0338492695. The cubic root of 9912001221 is about 2148.0964742673.

The spelling of 9912001221 in words is "nine billion, nine hundred twelve million, one thousand, two hundred twenty-one".