2155422421 has 2 divisors, whose sum is σ = 2155422422. Its totient is φ = 2155422420.

The previous prime is 2155422413. The next prime is 2155422433. The reversal of 2155422421 is 1242245512.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1893468196 + 261954225 = 43514^2 + 16185^2 .

It is a cyclic number.

It is not a de Polignac number, because 2155422421 - 2³ = 2155422413 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2155422421.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2155422121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1077711210 + 1077711211.

It is an arithmetic number, because the mean of its divisors is an integer number (1077711211).

Almost surely, 2^2155422421 is an apocalyptic number.

It is an amenable number.

2155422421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2155422421 is an equidigital number, since it uses as much as digits as its factorization.

2155422421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6400, while the sum is 28.

The square root of 2155422421 is about 46426.5271262023. The cubic root of 2155422421 is about 1291.7470112455.

Adding to 2155422421 its reverse (1242245512), we get a palindrome (3397667933).

The spelling of 2155422421 in words is "two billion, one hundred fifty-five million, four hundred twenty-two thousand, four hundred twenty-one".