155531201 has 4 divisors (see below), whose sum is σ = 177749952. Its totient is φ = 133312452.

The previous prime is 155531161. The next prime is 155531209. The reversal of 155531201 is 102135551.

It is a happy number.

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 not a de Polignac number, because 155531201 - 2⁶ = 155531137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (155531209) 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, 11109365 + ... + 11109378.

It is an arithmetic number, because the mean of its divisors is an integer number (44437488).

Almost surely, 2^155531201 is an apocalyptic number.

It is an amenable number.

155531201 is a deficient number, since it is larger than the sum of its proper divisors (22218751).

155531201 is an equidigital number, since it uses as much as digits as its factorization.

155531201 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22218750.

The product of its (nonzero) digits is 750, while the sum is 23.

The square root of 155531201 is about 12471.2148967132. The cubic root of 155531201 is about 537.7814798259.

Adding to 155531201 its reverse (102135551), we get a palindrome (257666752).

The spelling of 155531201 in words is "one hundred fifty-five million, five hundred thirty-one thousand, two hundred one".