145105021 has 2 divisors, whose sum is σ = 145105022. Its totient is φ = 145105020.

The previous prime is 145105007. The next prime is 145105039. The reversal of 145105021 is 120501541.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 143736121 + 1368900 = 11989^2 + 1170^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-145105021 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 145105021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (145108021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72552510 + 72552511.

It is an arithmetic number, because the mean of its divisors is an integer number (72552511).

Almost surely, 2^145105021 is an apocalyptic number.

It is an amenable number.

145105021 is a deficient number, since it is larger than the sum of its proper divisors (1).

145105021 is an equidigital number, since it uses as much as digits as its factorization.

145105021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 200, while the sum is 19.

The square root of 145105021 is about 12045.9545491422. The cubic root of 145105021 is about 525.4855927438.

Adding to 145105021 its reverse (120501541), we get a palindrome (265606562).

The spelling of 145105021 in words is "one hundred forty-five million, one hundred five thousand, twenty-one".