155211225 has 24 divisors (see below), whose sum is σ = 276357312. Its totient is φ = 76411200.

The previous prime is 155211223. The next prime is 155211229. The reversal of 155211225 is 522112551.

It is not a de Polignac number, because 155211225 - 2¹ = 155211223 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 155211195 and 155211204.

It is not an unprimeable number, because it can be changed into a prime (155211223) 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, 78621 + ... + 80570.

It is an arithmetic number, because the mean of its divisors is an integer number (11514888).

Almost surely, 2^155211225 is an apocalyptic number.

155211225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

155211225 is a deficient number, since it is larger than the sum of its proper divisors (121146087).

155211225 is a wasteful number, since it uses less digits than its factorization.

155211225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 159217 (or 159212 counting only the distinct ones).

The product of its digits is 1000, while the sum is 24.

The square root of 155211225 is about 12458.3797100586. The cubic root of 155211225 is about 537.4124321019.

Adding to 155211225 its reverse (522112551), we get a palindrome (677323776).

The spelling of 155211225 in words is "one hundred fifty-five million, two hundred eleven thousand, two hundred twenty-five".