1221121210999 has 8 divisors (see below), whose sum is σ = 1285561352880. Its totient is φ = 1156698129600.

The previous prime is 1221121210993. The next prime is 1221121211021. The reversal of 1221121210999 is 9990121211221.

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 1221121210999 - 2²⁵ = 1221087656567 is a prime.

It is a super-2 number, since 2×1221121210999² (a number of 25 digits) contains 22 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 (1221121210993) 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, 4118062 + ... + 4404619.

It is an arithmetic number, because the mean of its divisors is an integer number (160695169110).

Almost surely, 2^{1221121210999} is an apocalyptic number.

1221121210999 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

1221121210999 is a deficient number, since it is larger than the sum of its proper divisors (64440141881).

1221121210999 is an equidigital number, since it uses as much as digits as its factorization.

1221121210999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8530241.

The product of its (nonzero) digits is 11664, while the sum is 40.

The spelling of 1221121210999 in words is "one trillion, two hundred twenty-one billion, one hundred twenty-one million, two hundred ten thousand, nine hundred ninety-nine".