155320513 has 4 divisors (see below), whose sum is σ = 156109140. Its totient is φ = 154531888.

The previous prime is 155320511. The next prime is 155320547. The reversal of 155320513 is 315023551.

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 129686544 + 25633969 = 11388^2 + 5063^2 .

It is a cyclic number.

It is not a de Polignac number, because 155320513 - 2¹ = 155320511 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155320511) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 394018 + ... + 394411.

It is an arithmetic number, because the mean of its divisors is an integer number (39027285).

Almost surely, 2^155320513 is an apocalyptic number.

It is an amenable number.

155320513 is a deficient number, since it is larger than the sum of its proper divisors (788627).

155320513 is an equidigital number, since it uses as much as digits as its factorization.

155320513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 788626.

The product of its (nonzero) digits is 2250, while the sum is 25.

The square root of 155320513 is about 12462.7650623768. The cubic root of 155320513 is about 537.5385375650.

The spelling of 155320513 in words is "one hundred fifty-five million, three hundred twenty thousand, five hundred thirteen".