261864837696 has 112 divisors (see below), whose sum is σ = 863813928960. Its totient is φ = 68016837120.

The previous prime is 261864837691. The next prime is 261864837709. The reversal of 261864837696 is 696738468162.

It is a tau number, because it is divible by the number of its divisors (112).

It is a Harshad number since it is a multiple of its sum of digits (66).

It is not an unprimeable number, because it can be changed into a prime (261864837691) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8841576 + ... + 8871143.

Almost surely, 2^261864837696 is an apocalyptic number.

It is an amenable number.

261864837696 is an abundant number, since it is smaller than the sum of its proper divisors (601949091264).

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

261864837696 is a wasteful number, since it uses less digits than its factorization.

261864837696 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17712752 (or 17712742 counting only the distinct ones).

The product of its digits is 125411328, while the sum is 66.

The spelling of 261864837696 in words is "two hundred sixty-one billion, eight hundred sixty-four million, eight hundred thirty-seven thousand, six hundred ninety-six".