261630020736 has 192 divisors, whose sum is σ = 892288313280. Its totient is φ = 74751372288.

The previous prime is 261630020731. The next prime is 261630020749. The reversal of 261630020736 is 637020036162.

261630020736 is a `hidden beast` number, since 2 + 616 + 3 + 0 + 0 + 2 + 0 + 7 + 36 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

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

It is a self number, because there is not a number n which added to its sum of digits gives 261630020736.

It is not an unprimeable number, because it can be changed into a prime (261630020731) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 383091 + ... + 818546.

It is an arithmetic number, because the mean of its divisors is an integer number (4647334965).

Almost surely, 2^261630020736 is an apocalyptic number.

It is an amenable number.

261630020736 is an abundant number, since it is smaller than the sum of its proper divisors (630658292544).

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

261630020736 is an equidigital number, since it uses as much as digits as its factorization.

261630020736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1201673 (or 1201649 counting only the distinct ones).

The product of its (nonzero) digits is 54432, while the sum is 36.

Adding to 261630020736 its reverse (637020036162), we get a palindrome (898650056898).

The spelling of 261630020736 in words is "two hundred sixty-one billion, six hundred thirty million, twenty thousand, seven hundred thirty-six".