421091081 has 2 divisors, whose sum is σ = 421091082. Its totient is φ = 421091080.

The previous prime is 421091063. The next prime is 421091161. The reversal of 421091081 is 180190124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 419881081 + 1210000 = 20491^2 + 1100^2 .

It is a cyclic number.

It is not a de Polignac number, because 421091081 - 2¹⁰ = 421090057 is a prime.

It is a super-2 number, since 2×421091081² = 354635396995497122, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 421091081.

It is not a weakly prime, because it can be changed into another prime (421091381) 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, 210545540 + 210545541.

It is an arithmetic number, because the mean of its divisors is an integer number (210545541).

Almost surely, 2^421091081 is an apocalyptic number.

It is an amenable number.

421091081 is a deficient number, since it is larger than the sum of its proper divisors (1).

421091081 is an equidigital number, since it uses as much as digits as its factorization.

421091081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 421091081 is about 20520.5039168145. The cubic root of 421091081 is about 749.5351673744.

The spelling of 421091081 in words is "four hundred twenty-one million, ninety-one thousand, eighty-one".