261723226455678 has 64 divisors (see below), whose sum is σ = 598824453427200. Its totient is φ = 75591865975680.

The previous prime is 261723226455673. The next prime is 261723226455683. The reversal of 261723226455678 is 876554622327162.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (261723226455673) and next prime (261723226455683).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261723226455673) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 809936478 + ... + 810259553.

It is an arithmetic number, because the mean of its divisors is an integer number (9356632084800).

Almost surely, 2^{261723226455678} is an apocalyptic number.

261723226455678 is an abundant number, since it is smaller than the sum of its proper divisors (337101226971522).

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

261723226455678 is a wasteful number, since it uses less digits than its factorization.

261723226455678 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1620196177.

The product of its digits is 406425600, while the sum is 66.

The spelling of 261723226455678 in words is "two hundred sixty-one trillion, seven hundred twenty-three billion, two hundred twenty-six million, four hundred fifty-five thousand, six hundred seventy-eight".