155581249 has 2 divisors, whose sum is σ = 155581250. Its totient is φ = 155581248.

The previous prime is 155581247. The next prime is 155581271. The reversal of 155581249 is 942185551.

155581249 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 115347600 + 40233649 = 10740^2 + 6343^2 .

It is an emirp because it is prime and its reverse (942185551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 155581249 - 2¹ = 155581247 is a prime.

Together with 155581247, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (155581241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 77790624 + 77790625.

It is an arithmetic number, because the mean of its divisors is an integer number (77790625).

Almost surely, 2^155581249 is an apocalyptic number.

It is an amenable number.

155581249 is a deficient number, since it is larger than the sum of its proper divisors (1).

155581249 is an equidigital number, since it uses as much as digits as its factorization.

155581249 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72000, while the sum is 40.

The square root of 155581249 is about 12473.2212759976. The cubic root of 155581249 is about 537.8391574299.

It can be divided in two parts, 15558 and 1249, that added together give a 5-th power (16807 = 7⁵).

The spelling of 155581249 in words is "one hundred fifty-five million, five hundred eighty-one thousand, two hundred forty-nine".