155421169 has 4 divisors (see below), whose sum is σ = 155457396. Its totient is φ = 155384944.

The previous prime is 155421137. The next prime is 155421187. The reversal of 155421169 is 961124551.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 961124551 = 113 ⋅8505527.

It can be written as a sum of positive squares in 2 ways, for example, as 98267569 + 57153600 = 9913^2 + 7560^2 .

It is a cyclic number.

It is not a de Polignac number, because 155421169 - 2⁵ = 155421137 is a prime.

It is a super-2 number, since 2×155421169² = 48311479546653122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155421199) 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, 10654 + ... + 20599.

It is an arithmetic number, because the mean of its divisors is an integer number (38864349).

Almost surely, 2^155421169 is an apocalyptic number.

It is an amenable number.

155421169 is a deficient number, since it is larger than the sum of its proper divisors (36227).

155421169 is an equidigital number, since it uses as much as digits as its factorization.

155421169 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36226.

The product of its digits is 10800, while the sum is 34.

The square root of 155421169 is about 12466.8026775112. The cubic root of 155421169 is about 537.6546303983.

The spelling of 155421169 in words is "one hundred fifty-five million, four hundred twenty-one thousand, one hundred sixty-nine".