145581521 has 2 divisors, whose sum is σ = 145581522. Its totient is φ = 145581520.

The previous prime is 145581517. The next prime is 145581551. The reversal of 145581521 is 125185541.

145581521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 119683600 + 25897921 = 10940^2 + 5089^2 .

It is a cyclic number.

It is not a de Polignac number, because 145581521 - 2² = 145581517 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (145581551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72790760 + 72790761.

It is an arithmetic number, because the mean of its divisors is an integer number (72790761).

Almost surely, 2^145581521 is an apocalyptic number.

It is an amenable number.

145581521 is a deficient number, since it is larger than the sum of its proper divisors (1).

145581521 is an equidigital number, since it uses as much as digits as its factorization.

145581521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8000, while the sum is 32.

The square root of 145581521 is about 12065.7167627953. The cubic root of 145581521 is about 526.0601657866.

The spelling of 145581521 in words is "one hundred forty-five million, five hundred eighty-one thousand, five hundred twenty-one".