261245072160 has 216 divisors, whose sum is σ = 940891196700. Its totient is φ = 65998623744.

The previous prime is 261245072149. The next prime is 261245072191. The reversal of 261245072160 is 61270542162.

It is a happy number.

261245072160 is a `hidden beast` number, since 2 + 6 + 124 + 507 + 21 + 6 + 0 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 243210730896 + 18034341264 = 493164^2 + 134292^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 268566 + ... + 771114.

Almost surely, 2^261245072160 is an apocalyptic number.

261245072160 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 261245072160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (470445598350).

261245072160 is an abundant number, since it is smaller than the sum of its proper divisors (679646124540).

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

261245072160 is a wasteful number, since it uses less digits than its factorization.

261245072160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 502608 (or 502578 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 36.

The spelling of 261245072160 in words is "two hundred sixty-one billion, two hundred forty-five million, seventy-two thousand, one hundred sixty".