155511225 has 24 divisors (see below), whose sum is σ = 285681120. Its totient is φ = 82938960.

The previous prime is 155511217. The next prime is 155511227. The reversal of 155511225 is 522115551.

155511225 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 155511225 - 2³ = 155511217 is a prime.

It is a super-2 number, since 2×155511225² = 48367482202001250, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (155511227) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 114519 + ... + 115868.

It is an arithmetic number, because the mean of its divisors is an integer number (11903380).

Almost surely, 2^155511225 is an apocalyptic number.

155511225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

155511225 is a deficient number, since it is larger than the sum of its proper divisors (130169895).

155511225 is a wasteful number, since it uses less digits than its factorization.

155511225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230406 (or 230395 counting only the distinct ones).

The product of its digits is 2500, while the sum is 27.

The square root of 155511225 is about 12470.4139867127. The cubic root of 155511225 is about 537.7584551151.

Adding to 155511225 its reverse (522115551), we get a palindrome (677626776).

The spelling of 155511225 in words is "one hundred fifty-five million, five hundred eleven thousand, two hundred twenty-five".