261398016000 has 1248 divisors, whose sum is σ = 1071631282176. Its totient is φ = 63037440000.

The previous prime is 261398015969. The next prime is 261398016007. The reversal of 261398016000 is 610893162.

261398016000 is a `hidden beast` number, since 261 + 398 + 0 + 1 + 6 + 0 + 0 + 0 = 666.

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

It is not an unprimeable number, because it can be changed into a prime (261398016007) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 1368575905 + ... + 1368576095.

It is an arithmetic number, because the mean of its divisors is an integer number (858678912).

Almost surely, 2^261398016000 is an apocalyptic number.

261398016000 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 261398016000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (535815641088).

261398016000 is an abundant number, since it is smaller than the sum of its proper divisors (810233266176).

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

261398016000 is an equidigital number, since it uses as much as digits as its factorization.

261398016000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256 (or 212 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The spelling of 261398016000 in words is "two hundred sixty-one billion, three hundred ninety-eight million, sixteen thousand".