155204421 has 4 divisors (see below), whose sum is σ = 206939232. Its totient is φ = 103469612.

The previous prime is 155204419. The next prime is 155204443. The reversal of 155204421 is 124402551.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 155204421 - 2¹ = 155204419 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 155204391 and 155204400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (155204461) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25867401 + ... + 25867406.

It is an arithmetic number, because the mean of its divisors is an integer number (51734808).

Almost surely, 2^155204421 is an apocalyptic number.

It is an amenable number.

155204421 is a deficient number, since it is larger than the sum of its proper divisors (51734811).

155204421 is an equidigital number, since it uses as much as digits as its factorization.

155204421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51734810.

The product of its (nonzero) digits is 1600, while the sum is 24.

The square root of 155204421 is about 12458.1066378483. The cubic root of 155204421 is about 537.4045791312.

Adding to 155204421 its reverse (124402551), we get a palindrome (279606972).

The spelling of 155204421 in words is "one hundred fifty-five million, two hundred four thousand, four hundred twenty-one".