261221380226 has 16 divisors (see below), whose sum is σ = 392968420224. Its totient is φ = 130232031984.

The previous prime is 261221380213. The next prime is 261221380267. The reversal of 261221380226 is 622083122162.

It is a happy number.

It is a super-2 number, since 2×261221380226² (a number of 24 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4649861 + ... + 4705703.

It is an arithmetic number, because the mean of its divisors is an integer number (24560526264).

Almost surely, 2^261221380226 is an apocalyptic number.

261221380226 is a deficient number, since it is larger than the sum of its proper divisors (131747039998).

261221380226 is a wasteful number, since it uses less digits than its factorization.

261221380226 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62585.

The product of its (nonzero) digits is 27648, while the sum is 35.

The spelling of 261221380226 in words is "two hundred sixty-one billion, two hundred twenty-one million, three hundred eighty thousand, two hundred twenty-six".