155979909 has 6 divisors (see below), whose sum is σ = 225304326. Its totient is φ = 103986600.

The previous prime is 155979907. The next prime is 155979917. The reversal of 155979909 is 909979551.

It can be written as a sum of positive squares in only one way, i.e., 126495009 + 29484900 = 11247^2 + 5430^2 .

It is not a de Polignac number, because 155979909 - 2¹ = 155979907 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155979907) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8665542 + ... + 8665559.

It is an arithmetic number, because the mean of its divisors is an integer number (37550721).

Almost surely, 2^155979909 is an apocalyptic number.

It is an amenable number.

155979909 is a deficient number, since it is larger than the sum of its proper divisors (69324417).

155979909 is a wasteful number, since it uses less digits than its factorization.

155979909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17331107 (or 17331104 counting only the distinct ones).

The product of its (nonzero) digits is 1148175, while the sum is 54.

The square root of 155979909 is about 12489.1916872150. The cubic root of 155979909 is about 538.2981503609.

The spelling of 155979909 in words is "one hundred fifty-five million, nine hundred seventy-nine thousand, nine hundred nine".