261018810000 has 675 divisors, whose sum is σ = 996041677917. Its totient is φ = 63760320000.

The previous prime is 261018809977. The next prime is 261018810007. The reversal of 261018810000 is 18810162.

The square root of 261018810000 is 510900.

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

It can be written as a sum of positive squares in 7 ways, for example, as 257816155536 + 3202654464 = 507756^2 + 56592^2 .

It is a super-2 number, since 2×261018810000² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261018810007) by changing a digit.

It is a polite number, since it can be written in 134 ways as a sum of consecutive naturals, for example, 1992509935 + ... + 1992510065.

Almost surely, 2^261018810000 is an apocalyptic number.

261018810000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

261018810000 is the 510900-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261018810000

261018810000 is an abundant number, since it is smaller than the sum of its proper divisors (735022867917).

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

261018810000 is a wasteful number, since it uses less digits than its factorization.

261018810000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 322 (or 154 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 27.

The spelling of 261018810000 in words is "two hundred sixty-one billion, eighteen million, eight hundred ten thousand".