261543150476772 has 96 divisors (see below), whose sum is σ = 652938138058752. Its totient is φ = 81193945944576.

The previous prime is 261543150476711. The next prime is 261543150476791. The reversal of 261543150476772 is 277674051345162.

It is a happy number.

It is a super-2 number, since 2×261543150476772² (a number of 30 digits) contains 22 as substring.

It is an unprimeable number.

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, 22700893 + ... + 32224475.

It is an arithmetic number, because the mean of its divisors is an integer number (6801438938112).

Almost surely, 2^{261543150476772} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261543150476772, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (326469069029376).

261543150476772 is an abundant number, since it is smaller than the sum of its proper divisors (391394987581980).

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

261543150476772 is a wasteful number, since it uses less digits than its factorization.

261543150476772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9525017 (or 9525015 counting only the distinct ones).

The product of its (nonzero) digits is 59270400, while the sum is 60.

The spelling of 261543150476772 in words is "two hundred sixty-one trillion, five hundred forty-three billion, one hundred fifty million, four hundred seventy-six thousand, seven hundred seventy-two".