261973647360000 has 1275 divisors, whose sum is σ = 981530785867753. Its totient is φ = 69611028480000.

The previous prime is 261973647359959. The next prime is 261973647360001. The reversal of 261973647360000 is 63746379162.

It is a happy number.

The square root of 261973647360000 is 16185600.

It is a perfect power (a square), and thus also a powerful number.

261973647360000 is a `hidden beast` number, since 26 + 1 + 9 + 7 + 3 + 6 + 4 + 7 + 3 + 600 + 0 + 0 = 666.

It can be written as a sum of positive squares in 7 ways, for example, as 158078518493184 + 103895128866816 = 12572928^2 + 10192896^2 .

It is a super-2 number, since 2×261973647360000² (a number of 30 digits) contains 22 as substring.

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

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261973647360001) by changing a digit.

It is a polite number, since it can be written in 74 ways as a sum of consecutive naturals, for example, 932290559860 + ... + 932290560140.

Almost surely, 2^{261973647360000} is an apocalyptic number.

261973647360000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

261973647360000 is the 16185600-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261973647360000

261973647360000 is an abundant number, since it is smaller than the sum of its proper divisors (719557138507753).

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

261973647360000 is an frugal number, since it uses more digits than its factorization.

261973647360000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 626 (or 291 counting only the distinct ones).

The product of its (nonzero) digits is 6858432, while the sum is 54.

The spelling of 261973647360000 in words is "two hundred sixty-one trillion, nine hundred seventy-three billion, six hundred forty-seven million, three hundred sixty thousand".