65421 has 8 divisors (see below), whose sum is σ = 96960. Its totient is φ = 43596.

The previous prime is 65419. The next prime is 65423. The reversal of 65421 is 12456.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (65419) and next prime (65423).

It is not a de Polignac number, because 65421 - 2¹ = 65419 is a prime.

It is a Curzon number.

It is a nialpdrome in base 10.

It is a junction number, because it is equal to n+sod(n) for n = 65394 and 65403.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 65421.

It is not an unprimeable number, because it can be changed into a prime (65423) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1185 + ... + 1238.

It is an arithmetic number, because the mean of its divisors is an integer number (12120).

2⁶⁵⁴²¹ is an apocalyptic number.

It is an amenable number.

65421 is a deficient number, since it is larger than the sum of its proper divisors (31539).

65421 is a wasteful number, since it uses less digits than its factorization.

65421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2432 (or 2426 counting only the distinct ones).

The product of its digits is 240, while the sum is 18.

The square root of 65421 is about 255.7752920045. The cubic root of 65421 is about 40.2938772827.

Adding to 65421 its reverse (12456), we get a palindrome (77877).

The spelling of 65421 in words is "sixty-five thousand, four hundred twenty-one".