145421 has 4 divisors (see below), whose sum is σ = 150144. Its totient is φ = 140700.

The previous prime is 145417. The next prime is 145423. The reversal of 145421 is 124541.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 145421 - 2² = 145417 is a prime.

It is a super-2 number, since 2×145421² = 42294534482, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 145421.

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 145421.

It is not an unprimeable number, because it can be changed into a prime (145423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2315 + ... + 2376.

It is an arithmetic number, because the mean of its divisors is an integer number (37536).

2¹⁴⁵⁴²¹ is an apocalyptic number.

It is an amenable number.

145421 is a deficient number, since it is larger than the sum of its proper divisors (4723).

145421 is an equidigital number, since it uses as much as digits as its factorization.

145421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4722.

The product of its digits is 160, while the sum is 17.

The square root of 145421 is about 381.3410547004. The cubic root of 145421 is about 52.5866746643.

Adding to 145421 its reverse (124541), we get a palindrome (269962).

The spelling of 145421 in words is "one hundred forty-five thousand, four hundred twenty-one".