145452721 has 2 divisors, whose sum is σ = 145452722. Its totient is φ = 145452720.

The previous prime is 145452709. The next prime is 145452737. The reversal of 145452721 is 127254541.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 108680625 + 36772096 = 10425^2 + 6064^2 .

It is an emirp because it is prime and its reverse (127254541) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-145452721 is a prime.

It is an alternating number because its digits alternate between odd and even.

It is not a weakly prime, because it can be changed into another prime (145452701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72726360 + 72726361.

It is an arithmetic number, because the mean of its divisors is an integer number (72726361).

Almost surely, 2^145452721 is an apocalyptic number.

It is an amenable number.

145452721 is a deficient number, since it is larger than the sum of its proper divisors (1).

145452721 is an equidigital number, since it uses as much as digits as its factorization.

145452721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11200, while the sum is 31.

The square root of 145452721 is about 12060.3781449837. The cubic root of 145452721 is about 525.9049800168.

The spelling of 145452721 in words is "one hundred forty-five million, four hundred fifty-two thousand, seven hundred twenty-one".