72421 has 2 divisors, whose sum is σ = 72422. Its totient is φ = 72420.

The previous prime is 72383. The next prime is 72431. The reversal of 72421 is 12427.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 65025 + 7396 = 255^2 + 86^2 .

It is a cyclic number.

It is not a de Polignac number, because 72421 - 2⁹ = 71909 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 72395 and 72404.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (72431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 36210 + 36211.

It is an arithmetic number, because the mean of its divisors is an integer number (36211).

2⁷²⁴²¹ is an apocalyptic number.

It is an amenable number.

72421 is a deficient number, since it is larger than the sum of its proper divisors (1).

72421 is an equidigital number, since it uses as much as digits as its factorization.

72421 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 112, while the sum is 16.

The square root of 72421 is about 269.1115010549. Note that the first 3 decimals coincide. The cubic root of 72421 is about 41.6826036813.

Adding to 72421 its reverse (12427), we get a palindrome (84848).

The spelling of 72421 in words is "seventy-two thousand, four hundred twenty-one", and thus it is an iban number.