155002181 has 4 divisors (see below), whose sum is σ = 158782764. Its totient is φ = 151221600.

The previous prime is 155002163. The next prime is 155002231. The reversal of 155002181 is 181200551.

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 16728100 + 138274081 = 4090^2 + 11759^2 .

It is a cyclic number.

It is not a de Polignac number, because 155002181 - 2⁶ = 155002117 is a prime.

It is a super-2 number, since 2×155002181² = 48051352229513522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155008181) 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 3 ways as a sum of consecutive naturals, for example, 1890230 + ... + 1890311.

It is an arithmetic number, because the mean of its divisors is an integer number (39695691).

Almost surely, 2^155002181 is an apocalyptic number.

It is an amenable number.

155002181 is a deficient number, since it is larger than the sum of its proper divisors (3780583).

155002181 is an equidigital number, since it uses as much as digits as its factorization.

155002181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3780582.

The product of its (nonzero) digits is 400, while the sum is 23.

The square root of 155002181 is about 12449.9871887484. The cubic root of 155002181 is about 537.1710549764.

The spelling of 155002181 in words is "one hundred fifty-five million, two thousand, one hundred eighty-one".