145686521 has 2 divisors, whose sum is σ = 145686522. Its totient is φ = 145686520.

The previous prime is 145686491. The next prime is 145686529. The reversal of 145686521 is 125686541.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 139240000 + 6446521 = 11800^2 + 2539^2 .

It is an emirp because it is prime and its reverse (125686541) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 145686521 - 2¹⁰ = 145685497 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (145686529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72843260 + 72843261.

It is an arithmetic number, because the mean of its divisors is an integer number (72843261).

Almost surely, 2^145686521 is an apocalyptic number.

It is an amenable number.

145686521 is a deficient number, since it is larger than the sum of its proper divisors (1).

145686521 is an equidigital number, since it uses as much as digits as its factorization.

145686521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 57600, while the sum is 38.

The square root of 145686521 is about 12070.0671497718. The cubic root of 145686521 is about 526.1866082149.

The spelling of 145686521 in words is "one hundred forty-five million, six hundred eighty-six thousand, five hundred twenty-one".