309148281989 has 2 divisors, whose sum is σ = 309148281990. Its totient is φ = 309148281988.

The previous prime is 309148281977. The next prime is 309148282057. The reversal of 309148281989 is 989182841903.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 182388784900 + 126759497089 = 427070^2 + 356033^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-309148281989 is a prime.

It is a super-2 number, since 2×309148281989² (a number of 24 digits) contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (309148281929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 154574140994 + 154574140995.

It is an arithmetic number, because the mean of its divisors is an integer number (154574140995).

Almost surely, 2^309148281989 is an apocalyptic number.

It is an amenable number.

309148281989 is a deficient number, since it is larger than the sum of its proper divisors (1).

309148281989 is an equidigital number, since it uses as much as digits as its factorization.

309148281989 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8957952, while the sum is 62.

The spelling of 309148281989 in words is "three hundred nine billion, one hundred forty-eight million, two hundred eighty-one thousand, nine hundred eighty-nine".