2145202452221 has 2 divisors, whose sum is σ = 2145202452222. Its totient is φ = 2145202452220.

The previous prime is 2145202452137. The next prime is 2145202452227. The reversal of 2145202452221 is 1222542025412.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1835716072996 + 309486379225 = 1354886^2 + 556315^2 .

It is a cyclic number.

It is not a de Polignac number, because 2145202452221 - 2³⁸ = 1870324545277 is a prime.

It is a super-2 number, since 2×2145202452221² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2145202452227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1072601226110 + 1072601226111.

It is an arithmetic number, because the mean of its divisors is an integer number (1072601226111).

Almost surely, 2^{2145202452221} is an apocalyptic number.

It is an amenable number.

2145202452221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2145202452221 is an equidigital number, since it uses as much as digits as its factorization.

2145202452221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 25600, while the sum is 32.

Adding to 2145202452221 its reverse (1222542025412), we get a palindrome (3367744477633).

The spelling of 2145202452221 in words is "two trillion, one hundred forty-five billion, two hundred two million, four hundred fifty-two thousand, two hundred twenty-one".