261017225 has 24 divisors (see below), whose sum is σ = 385987200. Its totient is φ = 171198720.

The previous prime is 261017221. The next prime is 261017249. The reversal of 261017225 is 522710162.

It is not a de Polignac number, because 261017225 - 2² = 261017221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261017194 and 261017203.

It is not an unprimeable number, because it can be changed into a prime (261017221) 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, 28400 + ... + 36449.

It is an arithmetic number, because the mean of its divisors is an integer number (16082800).

Almost surely, 2^261017225 is an apocalyptic number.

261017225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

261017225 is a deficient number, since it is larger than the sum of its proper divisors (124969975).

261017225 is a wasteful number, since it uses less digits than its factorization.

261017225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64889 (or 64884 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 26.

The square root of 261017225 is about 16156.0275129748. The cubic root of 261017225 is about 639.0817112029.

Adding to 261017225 its reverse (522710162), we get a palindrome (783727387).

The spelling of 261017225 in words is "two hundred sixty-one million, seventeen thousand, two hundred twenty-five".