261778082022810 has 96 divisors (see below), whose sum is σ = 693526408743168. Its totient is φ = 68484296799360.

The previous prime is 261778082022803. The next prime is 261778082022817. The reversal of 261778082022810 is 18220280877162.

261778082022810 is a `hidden beast` number, since 2 + 617 + 7 + 8 + 0 + 8 + 2 + 0 + 2 + 2 + 8 + 10 = 666.

It is an interprime number because it is at equal distance from previous prime (261778082022803) and next prime (261778082022817).

It is a super-2 number, since 2×261778082022810² (a number of 30 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261778082022817) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 51527509 + ... + 56379431.

It is an arithmetic number, because the mean of its divisors is an integer number (7224233424408).

Almost surely, 2^{261778082022810} is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261778082022810, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (346763204371584).

261778082022810 is an abundant number, since it is smaller than the sum of its proper divisors (431748326720358).

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

261778082022810 is a wasteful number, since it uses less digits than its factorization.

261778082022810 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4863300 (or 4863297 counting only the distinct ones).

The product of its (nonzero) digits is 2408448, while the sum is 54.

The spelling of 261778082022810 in words is "two hundred sixty-one trillion, seven hundred seventy-eight billion, eighty-two million, twenty-two thousand, eight hundred ten".