261153801216 has 704 divisors, whose sum is σ = 980547717120. Its totient is φ = 66686976000.

The previous prime is 261153801199. The next prime is 261153801241. The reversal of 261153801216 is 612108351162.

261153801216 is a `hidden beast` number, since 2 + 61 + 1 + 5 + 380 + 1 + 216 = 666.

It is a tau number, because it is divible by the number of its divisors (704).

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 63 ways as a sum of consecutive naturals, for example, 129861651 + ... + 129863661.

Almost surely, 2^261153801216 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261153801216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (490273858560).

261153801216 is an abundant number, since it is smaller than the sum of its proper divisors (719393915904).

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

261153801216 is a wasteful number, since it uses less digits than its factorization.

261153801216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2119 (or 2095 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The spelling of 261153801216 in words is "two hundred sixty-one billion, one hundred fifty-three million, eight hundred one thousand, two hundred sixteen".