155520613 has 2 divisors, whose sum is σ = 155520614. Its totient is φ = 155520612.

The previous prime is 155520611. The next prime is 155520653. The reversal of 155520613 is 316025551.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122722084 + 32798529 = 11078^2 + 5727^2 .

It is an emirp because it is prime and its reverse (316025551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 155520613 - 2¹ = 155520611 is a prime.

It is a super-2 number, since 2×155520613² = 48373322135791538, which contains 22 as substring.

Together with 155520611, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (155520611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77760306 + 77760307.

It is an arithmetic number, because the mean of its divisors is an integer number (77760307).

Almost surely, 2^155520613 is an apocalyptic number.

It is an amenable number.

155520613 is a deficient number, since it is larger than the sum of its proper divisors (1).

155520613 is an equidigital number, since it uses as much as digits as its factorization.

155520613 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4500, while the sum is 28.

The square root of 155520613 is about 12470.7903919519. The cubic root of 155520613 is about 537.7692761449.

The spelling of 155520613 in words is "one hundred fifty-five million, five hundred twenty thousand, six hundred thirteen".