991212201 has 32 divisors (see below), whose sum is σ = 1709925120. Its totient is φ = 555714432.

The previous prime is 991212191. The next prime is 991212223. The reversal of 991212201 is 102212199.

991212201 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 991212201 - 2¹⁸ = 990950057 is a prime.

It is a super-2 number, since 2×991212201² = 1965003254822528802, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (991212601) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 39460 + ... + 59493.

It is an arithmetic number, because the mean of its divisors is an integer number (53435160).

Almost surely, 2^991212201 is an apocalyptic number.

It is an amenable number.

991212201 is a deficient number, since it is larger than the sum of its proper divisors (718712919).

991212201 is a wasteful number, since it uses less digits than its factorization.

991212201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 99022 (or 99016 counting only the distinct ones).

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

The square root of 991212201 is about 31483.5226904487. The cubic root of 991212201 is about 997.0621109270.

The spelling of 991212201 in words is "nine hundred ninety-one million, two hundred twelve thousand, two hundred one".