8434401921 has 63 divisors (see below), whose sum is σ = 14009326513. Its totient is φ = 4889508360.

The previous prime is 8434401919. The next prime is 8434402003. The reversal of 8434401921 is 1291044348.

It is a happy number.

The square root of 8434401921 is 91839.

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

It is not a de Polignac number, because 8434401921 - 2¹ = 8434401919 is a prime.

It is a super-2 number, since 2×8434401921² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (8434401901) 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 in 62 ways as a sum of consecutive naturals, for example, 366713116 + ... + 366713138.

Almost surely, 2^8434401921 is an apocalyptic number.

8434401921 is the 91839-th square number.

8434401921 is the 45920-th centered octagonal number.

It is an amenable number.

8434401921 is a deficient number, since it is larger than the sum of its proper divisors (5574924592).

8434401921 is an frugal number, since it uses more digits than its factorization.

8434401921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118 (or 37 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 36.

The cubic root of 8434401921 is about 2035.5640121591.

Multiplying 8434401921 by its sum of digits (36), we get a square (303638469156 = 551034²).

The spelling of 8434401921 in words is "eight billion, four hundred thirty-four million, four hundred one thousand, nine hundred twenty-one".