2155923421 has 2 divisors, whose sum is σ = 2155923422. Its totient is φ = 2155923420.

The previous prime is 2155923403. The next prime is 2155923439. The reversal of 2155923421 is 1243295512.

It is a balanced prime because it is at equal distance from previous prime (2155923403) and next prime (2155923439).

It can be written as a sum of positive squares in only one way, i.e., 1798184025 + 357739396 = 42405^2 + 18914^2 .

It is a cyclic number.

It is not a de Polignac number, because 2155923421 - 2⁵ = 2155923389 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2155920421) 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, 1077961710 + 1077961711.

It is an arithmetic number, because the mean of its divisors is an integer number (1077961711).

Almost surely, 2^2155923421 is an apocalyptic number.

It is an amenable number.

2155923421 is a deficient number, since it is larger than the sum of its proper divisors (1).

2155923421 is an equidigital number, since it uses as much as digits as its factorization.

2155923421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21600, while the sum is 34.

The square root of 2155923421 is about 46431.9224348939. The cubic root of 2155923421 is about 1291.8470867746.

The spelling of 2155923421 in words is "two billion, one hundred fifty-five million, nine hundred twenty-three thousand, four hundred twenty-one".