261555222 has 8 divisors (see below), whose sum is σ = 523110456. Its totient is φ = 87185072.

The previous prime is 261555221. The next prime is 261555269. The reversal of 261555222 is 222555162.

It is a sphenic number, since it is the product of 3 distinct primes.

261555222 is an admirable number.

It is a super-2 number, since 2×261555222² = 136822268310938568, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 261555222.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261555221) 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, 21796263 + ... + 21796274.

It is an arithmetic number, because the mean of its divisors is an integer number (65388807).

Almost surely, 2^261555222 is an apocalyptic number.

261555222 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

261555222 is a wasteful number, since it uses less digits than its factorization.

261555222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43592542.

The product of its digits is 12000, while the sum is 30.

The square root of 261555222 is about 16172.6689819584. The cubic root of 261555222 is about 639.5204920644.

The spelling of 261555222 in words is "two hundred sixty-one million, five hundred fifty-five thousand, two hundred twenty-two".