261948411648 has 1080 divisors, whose sum is σ = 1035318049920. Its totient is φ = 65016483840.

The previous prime is 261948411631. The next prime is 261948411721. The reversal of 261948411648 is 846114849162.

261948411648 is a `hidden beast` number, since 2 + 6 + 1 + 9 + 484 + 116 + 48 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 261948411594 and 261948411603.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 257063683 + ... + 257064701.

It is an arithmetic number, because the mean of its divisors is an integer number (958627824).

Almost surely, 2^261948411648 is an apocalyptic number.

261948411648 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261948411648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (517659024960).

261948411648 is an abundant number, since it is smaller than the sum of its proper divisors (773369638272).

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

261948411648 is a wasteful number, since it uses less digits than its factorization.

261948411648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1095 (or 1065 counting only the distinct ones).

The product of its digits is 2654208, while the sum is 54.

The spelling of 261948411648 in words is "two hundred sixty-one billion, nine hundred forty-eight million, four hundred eleven thousand, six hundred forty-eight".