421643734281 has 135 divisors (see below), whose sum is σ = 806222270007. Its totient is φ = 218801943360.

The previous prime is 421643734271. The next prime is 421643734283. The reversal of 421643734281 is 182437346124.

The square root of 421643734281 is 649341.

It is a perfect power (a square), and thus also a powerful number.

421643734281 is a `hidden beast` number, since 4 + 2 + 164 + 373 + 42 + 81 = 666.

It can be written as a sum of positive squares in only one way, i.e., 22199510025 + 399444224256 = 148995^2 + 632016^2 .

It is not a de Polignac number, because 421643734281 - 2⁹ = 421643733769 is a prime.

It is a super-2 number, since 2×421643734281² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (421643734283) 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 in 134 ways as a sum of consecutive naturals, for example, 449992845 + ... + 449993781.

Almost surely, 2^421643734281 is an apocalyptic number.

421643734281 is the 649341-st square number.

421643734281 is the 324671-st centered octagonal number.

It is an amenable number.

421643734281 is a deficient number, since it is larger than the sum of its proper divisors (384578535726).

421643734281 is an frugal number, since it uses more digits than its factorization.

421643734281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1922 (or 958 counting only the distinct ones).

The product of its digits is 774144, while the sum is 45.

The spelling of 421643734281 in words is "four hundred twenty-one billion, six hundred forty-three million, seven hundred thirty-four thousand, two hundred eighty-one".