1212111221001 has 4 divisors (see below), whose sum is σ = 1616148294672. Its totient is φ = 808074147332.

The previous prime is 1212111220927. The next prime is 1212111221023. The reversal of 1212111221001 is 1001221112121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1212111221001 - 2¹⁷ = 1212111089929 is a prime.

It is a super-2 number, since 2×1212111221001² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1212111221801) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 202018536831 + ... + 202018536836.

It is an arithmetic number, because the mean of its divisors is an integer number (404037073668).

Almost surely, 2^{1212111221001} is an apocalyptic number.

It is an amenable number.

1212111221001 is a deficient number, since it is larger than the sum of its proper divisors (404037073671).

1212111221001 is an equidigital number, since it uses as much as digits as its factorization.

1212111221001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404037073670.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1212111221001 its reverse (1001221112121), we get a palindrome (2213332333122).

The spelling of 1212111221001 in words is "one trillion, two hundred twelve billion, one hundred eleven million, two hundred twenty-one thousand, one".