261225156 has 48 divisors (see below), whose sum is σ = 634334400. Its totient is φ = 83567232.

The previous prime is 261225137. The next prime is 261225163. The reversal of 261225156 is 651522162.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 58035 + ... + 62373.

It is an arithmetic number, because the mean of its divisors is an integer number (13215300).

Almost surely, 2^261225156 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261225156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (317167200).

261225156 is an abundant number, since it is smaller than the sum of its proper divisors (373109244).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261225156 is a wasteful number, since it uses less digits than its factorization.

261225156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4548 (or 4546 counting only the distinct ones).

The product of its digits is 7200, while the sum is 30.

The square root of 261225156 is about 16162.4613224595. The cubic root of 261225156 is about 639.2513674758.

The spelling of 261225156 in words is "two hundred sixty-one million, two hundred twenty-five thousand, one hundred fifty-six".