421601641 has 2 divisors, whose sum is σ = 421601642. Its totient is φ = 421601640.

The previous prime is 421601639. The next prime is 421601657. The reversal of 421601641 is 146106124.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 392872041 + 28729600 = 19821^2 + 5360^2 .

It is a cyclic number.

It is not a de Polignac number, because 421601641 - 2¹ = 421601639 is a prime.

Together with 421601639, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (421601611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210800820 + 210800821.

It is an arithmetic number, because the mean of its divisors is an integer number (210800821).

Almost surely, 2^421601641 is an apocalyptic number.

It is an amenable number.

421601641 is a deficient number, since it is larger than the sum of its proper divisors (1).

421601641 is an equidigital number, since it uses as much as digits as its factorization.

421601641 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1152, while the sum is 25.

The square root of 421601641 is about 20532.9403885561. The cubic root of 421601641 is about 749.8379744810.

Adding to 421601641 its reverse (146106124), we get a palindrome (567707765).

The spelling of 421601641 in words is "four hundred twenty-one million, six hundred one thousand, six hundred forty-one".