145786721 has 2 divisors, whose sum is σ = 145786722. Its totient is φ = 145786720.

The previous prime is 145786709. The next prime is 145786757. The reversal of 145786721 is 127687541.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 133980625 + 11806096 = 11575^2 + 3436^2 .

It is an emirp because it is prime and its reverse (127687541) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-145786721 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (145786321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 72893360 + 72893361.

It is an arithmetic number, because the mean of its divisors is an integer number (72893361).

Almost surely, 2^145786721 is an apocalyptic number.

It is an amenable number.

145786721 is a deficient number, since it is larger than the sum of its proper divisors (1).

145786721 is an equidigital number, since it uses as much as digits as its factorization.

145786721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 94080, while the sum is 41.

The square root of 145786721 is about 12074.2172002992. The cubic root of 145786721 is about 526.3072137794.

The spelling of 145786721 in words is "one hundred forty-five million, seven hundred eighty-six thousand, seven hundred twenty-one".