155218249 has 4 divisors (see below), whose sum is σ = 155386260. Its totient is φ = 155050240.

The previous prime is 155218213. The next prime is 155218253. The reversal of 155218249 is 942812551.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 942812551 = 4649 ⋅202799.

It can be written as a sum of positive squares in 2 ways, for example, as 22231225 + 132987024 = 4715^2 + 11532^2 .

It is a cyclic number.

It is not a de Polignac number, because 155218249 - 2¹³ = 155210057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155818249) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82612 + ... + 84469.

It is an arithmetic number, because the mean of its divisors is an integer number (38846565).

Almost surely, 2^155218249 is an apocalyptic number.

It is an amenable number.

155218249 is a deficient number, since it is larger than the sum of its proper divisors (168011).

155218249 is an equidigital number, since it uses as much as digits as its factorization.

155218249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168010.

The product of its digits is 28800, while the sum is 37.

The square root of 155218249 is about 12458.6616054856. The cubic root of 155218249 is about 537.4205387492.

The spelling of 155218249 in words is "one hundred fifty-five million, two hundred eighteen thousand, two hundred forty-nine".