8129421 has 6 divisors (see below), whose sum is σ = 11742510. Its totient is φ = 5419608.

The previous prime is 8129413. The next prime is 8129431. The reversal of 8129421 is 1249218.

It can be written as a sum of positive squares in only one way, i.e., 6200100 + 1929321 = 2490^2 + 1389^2 .

It is not a de Polignac number, because 8129421 - 2³ = 8129413 is a prime.

It is a Curzon number.

It is a plaindrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8129411) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 451626 + ... + 451643.

It is an arithmetic number, because the mean of its divisors is an integer number (1957085).

Almost surely, 2^8129421 is an apocalyptic number.

It is an amenable number.

8129421 is a deficient number, since it is larger than the sum of its proper divisors (3613089).

8129421 is a wasteful number, since it uses less digits than its factorization.

8129421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 903275 (or 903272 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 8129421 is about 2851.2139519861. The cubic root of 8129421 is about 201.0727441459.

The spelling of 8129421 in words is "eight million, one hundred twenty-nine thousand, four hundred twenty-one".