1211220210999 has 8 divisors (see below), whose sum is σ = 1639064166400. Its totient is φ = 795428198136.

The previous prime is 1211220210973. The next prime is 1211220211007. The reversal of 1211220210999 is 9990120221121.

It is a happy number.

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

It is not a de Polignac number, because 1211220210999 - 2²³ = 1211211822391 is a prime.

It is a super-4 number, since 4×1211220210999⁴ (a number of 49 digits) contains 4444 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211220210929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3012985399 + ... + 3012985800.

It is an arithmetic number, because the mean of its divisors is an integer number (204883020800).

Almost surely, 2^{1211220210999} is an apocalyptic number.

1211220210999 is a deficient number, since it is larger than the sum of its proper divisors (427843955401).

1211220210999 is an equidigital number, since it uses as much as digits as its factorization.

1211220210999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6025971269.

The product of its (nonzero) digits is 11664, while the sum is 39.

The spelling of 1211220210999 in words is "one trillion, two hundred eleven billion, two hundred twenty million, two hundred ten thousand, nine hundred ninety-nine".