426421661 has 2 divisors, whose sum is σ = 426421662. Its totient is φ = 426421660.

The previous prime is 426421651. The next prime is 426421663. The reversal of 426421661 is 166124624.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 302099161 + 124322500 = 17381^2 + 11150^2 .

It is a cyclic number.

It is not a de Polignac number, because 426421661 - 2²⁶ = 359312797 is a prime.

It is a Sophie Germain prime.

Together with 426421663, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (426421663) 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, 213210830 + 213210831.

It is an arithmetic number, because the mean of its divisors is an integer number (213210831).

Almost surely, 2^426421661 is an apocalyptic number.

It is an amenable number.

426421661 is a deficient number, since it is larger than the sum of its proper divisors (1).

426421661 is an equidigital number, since it uses as much as digits as its factorization.

426421661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13824, while the sum is 32.

The square root of 426421661 is about 20649.9796852200. The cubic root of 426421661 is about 752.6846960391.

The spelling of 426421661 in words is "four hundred twenty-six million, four hundred twenty-one thousand, six hundred sixty-one".