7890221121001 has 2 divisors, whose sum is σ = 7890221121002. Its totient is φ = 7890221121000.

The previous prime is 7890221120923. The next prime is 7890221121061. The reversal of 7890221121001 is 1001211220987.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7467949890025 + 422271230976 = 2732755^2 + 649824^2 .

It is an emirp because it is prime and its reverse (1001211220987) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7890221121001 - 2¹¹ = 7890221118953 is a prime.

It is not a weakly prime, because it can be changed into another prime (7890221121061) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3945110560500 + 3945110560501.

It is an arithmetic number, because the mean of its divisors is an integer number (3945110560501).

Almost surely, 2^{7890221121001} is an apocalyptic number.

It is an amenable number.

7890221121001 is a deficient number, since it is larger than the sum of its proper divisors (1).

7890221121001 is an equidigital number, since it uses as much as digits as its factorization.

7890221121001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4032, while the sum is 34.

Adding to 7890221121001 its reverse (1001211220987), we get a palindrome (8891432341988).

The spelling of 7890221121001 in words is "seven trillion, eight hundred ninety billion, two hundred twenty-one million, one hundred twenty-one thousand, one".