155439308909 has 2 divisors, whose sum is σ = 155439308910. Its totient is φ = 155439308908.

The previous prime is 155439308881. The next prime is 155439308939. The reversal of 155439308909 is 909803934551.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 155435428009 + 3880900 = 394253^2 + 1970^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-155439308909 is a prime.

It is a super-2 number, since 2×155439308909² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155439308939) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77719654454 + 77719654455.

It is an arithmetic number, because the mean of its divisors is an integer number (77719654455).

Almost surely, 2^155439308909 is an apocalyptic number.

It is an amenable number.

155439308909 is a deficient number, since it is larger than the sum of its proper divisors (1).

155439308909 is an equidigital number, since it uses as much as digits as its factorization.

155439308909 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5248800, while the sum is 56.

The spelling of 155439308909 in words is "one hundred fifty-five billion, four hundred thirty-nine million, three hundred eight thousand, nine hundred nine".