261226405 has 8 divisors (see below), whose sum is σ = 341969184. Its totient is φ = 189982800.

The previous prime is 261226393. The next prime is 261226411. The reversal of 261226405 is 504622162.

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

It is not a de Polignac number, because 261226405 - 2⁵ = 261226373 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2374731 + ... + 2374840.

It is an arithmetic number, because the mean of its divisors is an integer number (42746148).

Almost surely, 2^261226405 is an apocalyptic number.

It is an amenable number.

261226405 is a deficient number, since it is larger than the sum of its proper divisors (80742779).

261226405 is a wasteful number, since it uses less digits than its factorization.

261226405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4749587.

The product of its (nonzero) digits is 5760, while the sum is 28.

The square root of 261226405 is about 16162.4999613302. The cubic root of 261226405 is about 639.2523862951.

Adding to 261226405 its reverse (504622162), we get a palindrome (765848567).

The spelling of 261226405 in words is "two hundred sixty-one million, two hundred twenty-six thousand, four hundred five".