261660131041500 has 192 divisors, whose sum is σ = 846651693888000. Its totient is φ = 69773084136000.

The previous prime is 261660131041487. The next prime is 261660131041577. The reversal of 261660131041500 is 5140131066162.

261660131041500 is a `hidden beast` number, since 2 + 6 + 1 + 6 + 601 + 3 + 1 + 0 + 41 + 5 + 0 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

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 63 ways as a sum of consecutive naturals, for example, 328610851 + ... + 329406149.

It is an arithmetic number, because the mean of its divisors is an integer number (4409644239000).

Almost surely, 2^{261660131041500} is an apocalyptic number.

261660131041500 is a gapful number since it is divisible by the number (20) 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 261660131041500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (423325846944000).

261660131041500 is an abundant number, since it is smaller than the sum of its proper divisors (584991562846500).

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

261660131041500 is a wasteful number, since it uses less digits than its factorization.

261660131041500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 819698 (or 819680 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The spelling of 261660131041500 in words is "two hundred sixty-one trillion, six hundred sixty billion, one hundred thirty-one million, forty-one thousand, five hundred".