155665013 has 6 divisors (see below), whose sum is σ = 181079766. Its totient is φ = 133427112.

The previous prime is 155665009. The next prime is 155665021. The reversal of 155665013 is 310566551.

It can be written as a sum of positive squares in only one way, i.e., 152819044 + 2845969 = 12362^2 + 1687^2 .

It is not a de Polignac number, because 155665013 - 2² = 155665009 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155665093) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1588370 + ... + 1588467.

It is an arithmetic number, because the mean of its divisors is an integer number (30179961).

Almost surely, 2^155665013 is an apocalyptic number.

It is an amenable number.

155665013 is a deficient number, since it is larger than the sum of its proper divisors (25414753).

155665013 is an equidigital number, since it uses as much as digits as its factorization.

155665013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3176851 (or 3176844 counting only the distinct ones).

The product of its (nonzero) digits is 13500, while the sum is 32.

The square root of 155665013 is about 12476.5785774787. The cubic root of 155665013 is about 537.9356632251.

The spelling of 155665013 in words is "one hundred fifty-five million, six hundred sixty-five thousand, thirteen".