1001212001221 has 4 divisors (see below), whose sum is σ = 1001519974944. Its totient is φ = 1000904027500.

The previous prime is 1001212001219. The next prime is 1001212001267. The reversal of 1001212001221 is 1221002121001.

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 1001212001221 - 2¹ = 1001212001219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1001212001021) 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, 153981985 + ... + 153988486.

It is an arithmetic number, because the mean of its divisors is an integer number (250379993736).

Almost surely, 2^{1001212001221} is an apocalyptic number.

It is an amenable number.

1001212001221 is a deficient number, since it is larger than the sum of its proper divisors (307973723).

1001212001221 is an equidigital number, since it uses as much as digits as its factorization.

1001212001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 307973722.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 1001212001221 its reverse (1221002121001), we get a palindrome (2222214122222).

The spelling of 1001212001221 in words is "one trillion, one billion, two hundred twelve million, one thousand, two hundred twenty-one".