155977109 has 4 divisors (see below), whose sum is σ = 161355660. Its totient is φ = 150598560.

The previous prime is 155977093. The next prime is 155977121. The reversal of 155977109 is 901779551.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 93219025 + 62758084 = 9655^2 + 7922^2 .

It is a cyclic number.

It is not a de Polignac number, because 155977109 - 2⁴ = 155977093 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 155977109.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155977189) 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 in 3 ways as a sum of consecutive naturals, for example, 2689232 + ... + 2689289.

It is an arithmetic number, because the mean of its divisors is an integer number (40338915).

Almost surely, 2^155977109 is an apocalyptic number.

It is an amenable number.

155977109 is a deficient number, since it is larger than the sum of its proper divisors (5378551).

155977109 is an equidigital number, since it uses as much as digits as its factorization.

155977109 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5378550.

The product of its (nonzero) digits is 99225, while the sum is 44.

The square root of 155977109 is about 12489.0795897856. The cubic root of 155977109 is about 538.2949293396.

The spelling of 155977109 in words is "one hundred fifty-five million, nine hundred seventy-seven thousand, one hundred nine".