9999012221 has 8 divisors (see below), whose sum is σ = 11016014688. Its totient is φ = 9000010000.

The previous prime is 9999012173. The next prime is 9999012269. The reversal of 9999012221 is 1222109999.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (9999012173) and next prime (9999012269).

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

It is a cyclic number.

It is not a de Polignac number, because 9999012221 - 2¹⁸ = 9998750077 is a prime.

It is a Duffinian number.

9999012221 is a modest number, since divided by 12221 gives 9999 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9999212221) 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, 4498895 + ... + 4501116.

It is an arithmetic number, because the mean of its divisors is an integer number (1377001836).

Almost surely, 2^9999012221 is an apocalyptic number.

It is an amenable number.

9999012221 is a deficient number, since it is larger than the sum of its proper divisors (1017002467).

9999012221 is a wasteful number, since it uses less digits than its factorization.

9999012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9000123.

The product of its (nonzero) digits is 52488, while the sum is 44.

The square root of 9999012221 is about 99995.0609830306. The cubic root of 9999012221 is about 2154.3637508513.

It can be divided in two parts, 99990 and 12221, that added together give a palindrome (112211).

The spelling of 9999012221 in words is "nine billion, nine hundred ninety-nine million, twelve thousand, two hundred twenty-one".