145221393 has 4 divisors (see below), whose sum is σ = 193628528. Its totient is φ = 96814260.

The previous prime is 145221367. The next prime is 145221413. The reversal of 145221393 is 393122541.

145221393 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 de Polignac number, because none of the positive numbers 2^k-145221393 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 145221393.

It is not an unprimeable number, because it can be changed into a prime (145220393) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24203563 + ... + 24203568.

It is an arithmetic number, because the mean of its divisors is an integer number (48407132).

Almost surely, 2^145221393 is an apocalyptic number.

It is an amenable number.

145221393 is a deficient number, since it is larger than the sum of its proper divisors (48407135).

145221393 is an equidigital number, since it uses as much as digits as its factorization.

145221393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 48407134.

The product of its digits is 6480, while the sum is 30.

The square root of 145221393 is about 12050.7839164098. The cubic root of 145221393 is about 525.6260323340.

The spelling of 145221393 in words is "one hundred forty-five million, two hundred twenty-one thousand, three hundred ninety-three".