421220639869 has 2 divisors, whose sum is σ = 421220639870. Its totient is φ = 421220639868.

The previous prime is 421220639789. The next prime is 421220639881. The reversal of 421220639869 is 968936022124.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 345524122969 + 75696516900 = 587813^2 + 275130^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-421220639869 is a prime.

It is a super-2 number, since 2×421220639869² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (421220639069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210610319934 + 210610319935.

It is an arithmetic number, because the mean of its divisors is an integer number (210610319935).

Almost surely, 2^421220639869 is an apocalyptic number.

It is an amenable number.

421220639869 is a deficient number, since it is larger than the sum of its proper divisors (1).

421220639869 is an equidigital number, since it uses as much as digits as its factorization.

421220639869 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2239488, while the sum is 52.

The spelling of 421220639869 in words is "four hundred twenty-one billion, two hundred twenty million, six hundred thirty-nine thousand, eight hundred sixty-nine".