1791478421 has 2 divisors, whose sum is σ = 1791478422. Its totient is φ = 1791478420.

The previous prime is 1791478417. The next prime is 1791478453. The reversal of 1791478421 is 1248741971.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1647142225 + 144336196 = 40585^2 + 12014^2 .

It is a cyclic number.

It is not a de Polignac number, because 1791478421 - 2² = 1791478417 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1791478621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 895739210 + 895739211.

It is an arithmetic number, because the mean of its divisors is an integer number (895739211).

Almost surely, 2^1791478421 is an apocalyptic number.

It is an amenable number.

1791478421 is a deficient number, since it is larger than the sum of its proper divisors (1).

1791478421 is an equidigital number, since it uses as much as digits as its factorization.

1791478421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 112896, while the sum is 44.

The square root of 1791478421 is about 42325.8599558237. The cubic root of 1791478421 is about 1214.5177334879.

The spelling of 1791478421 in words is "one billion, seven hundred ninety-one million, four hundred seventy-eight thousand, four hundred twenty-one".