145388821 has 2 divisors, whose sum is σ = 145388822. Its totient is φ = 145388820.

The previous prime is 145388731. The next prime is 145388827. The reversal of 145388821 is 128883541.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 135466321 + 9922500 = 11639^2 + 3150^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-145388821 is a prime.

It is a super-2 number, since 2×145388821² = 42275818543540082, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (145388827) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72694410 + 72694411.

It is an arithmetic number, because the mean of its divisors is an integer number (72694411).

Almost surely, 2^145388821 is an apocalyptic number.

It is an amenable number.

145388821 is a deficient number, since it is larger than the sum of its proper divisors (1).

145388821 is an equidigital number, since it uses as much as digits as its factorization.

145388821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 61440, while the sum is 40.

The square root of 145388821 is about 12057.7286832969. The cubic root of 145388821 is about 525.8279555598.

It can be divided in two parts, 14 and 5388821, that added together give a palindrome (5388835).

The spelling of 145388821 in words is "one hundred forty-five million, three hundred eighty-eight thousand, eight hundred twenty-one".