155516813 has 8 divisors (see below), whose sum is σ = 160385400. Its totient is φ = 150699520.

The previous prime is 155516807. The next prime is 155516827. The reversal of 155516813 is 318615551.

It can be written as a sum of positive squares in 4 ways, for example, as 26399044 + 129117769 = 5138^2 + 11363^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 155516813 - 2⁴ = 155516797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155516213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6620 + ... + 18837.

It is an arithmetic number, because the mean of its divisors is an integer number (20048175).

Almost surely, 2^155516813 is an apocalyptic number.

It is an amenable number.

155516813 is a deficient number, since it is larger than the sum of its proper divisors (4868587).

155516813 is a wasteful number, since it uses less digits than its factorization.

155516813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25647.

The product of its digits is 18000, while the sum is 35.

The square root of 155516813 is about 12470.6380350005. The cubic root of 155516813 is about 537.7648961469.

The spelling of 155516813 in words is "one hundred fifty-five million, five hundred sixteen thousand, eight hundred thirteen".