261788981015436 has 24 divisors (see below), whose sum is σ = 698103949374720. Its totient is φ = 74796851718672.

The previous prime is 261788981015431. The next prime is 261788981015489. The reversal of 261788981015436 is 634510189887162.

It is a super-2 number, since 2×261788981015436² (a number of 30 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (261788981015431) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1558267744056 + ... + 1558267744223.

It is an arithmetic number, because the mean of its divisors is an integer number (29087664557280).

It is a 1-persistent number, because it is pandigital, but 2⋅261788981015436 = 523577962030872 is not.

Almost surely, 2^{261788981015436} is an apocalyptic number.

It is an amenable number.

261788981015436 is an abundant number, since it is smaller than the sum of its proper divisors (436314968359284).

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

261788981015436 is a wasteful number, since it uses less digits than its factorization.

261788981015436 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3116535488293 (or 3116535488291 counting only the distinct ones).

The product of its (nonzero) digits is 139345920, while the sum is 69.

The spelling of 261788981015436 in words is "two hundred sixty-one trillion, seven hundred eighty-eight billion, nine hundred eighty-one million, fifteen thousand, four hundred thirty-six".