8425217421 has 12 divisors (see below), whose sum is σ = 12178717980. Its totient is φ = 5612676480.

The previous prime is 8425217413. The next prime is 8425217461. The reversal of 8425217421 is 1247125248.

8425217421 is a `hidden beast` number, since 8 + 42 + 521 + 74 + 21 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 3009729321 + 5415488100 = 54861^2 + 73590^2 .

It is not a de Polignac number, because 8425217421 - 2³ = 8425217413 is a prime.

It is a super-2 number, since 2×8425217421² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8425217461) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 331666 + ... + 356163.

It is an arithmetic number, because the mean of its divisors is an integer number (1014893165).

Almost surely, 2^8425217421 is an apocalyptic number.

It is an amenable number.

8425217421 is a deficient number, since it is larger than the sum of its proper divisors (3753500559).

8425217421 is a wasteful number, since it uses less digits than its factorization.

8425217421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 689196 (or 689193 counting only the distinct ones).

The product of its digits is 35840, while the sum is 36.

The square root of 8425217421 is about 91788.9831134434. The cubic root of 8425217421 is about 2034.8248794163.

The spelling of 8425217421 in words is "eight billion, four hundred twenty-five million, two hundred seventeen thousand, four hundred twenty-one".