155204121 has 8 divisors (see below), whose sum is σ = 207010944. Its totient is φ = 103433360.

The previous prime is 155204057. The next prime is 155204129. The reversal of 155204121 is 121402551.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 155204121 - 2⁶ = 155204057 is a prime.

It is not an unprimeable number, because it can be changed into a prime (155204129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3520 + ... + 17966.

It is an arithmetic number, because the mean of its divisors is an integer number (25876368).

Almost surely, 2^155204121 is an apocalyptic number.

It is an amenable number.

155204121 is a deficient number, since it is larger than the sum of its proper divisors (51806823).

155204121 is a wasteful number, since it uses less digits than its factorization.

155204121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18031.

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 155204121 is about 12458.0945974896. The cubic root of 155204121 is about 537.4042328750.

Adding to 155204121 its reverse (121402551), we get a palindrome (276606672).

The spelling of 155204121 in words is "one hundred fifty-five million, two hundred four thousand, one hundred twenty-one".