261305612040 has 64 divisors (see below), whose sum is σ = 855182007360. Its totient is φ = 63346814720.

The previous prime is 261305612023. The next prime is 261305612047. The reversal of 261305612040 is 40216503162.

261305612040 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 261305611989 and 261305612007.

It is not an unprimeable number, because it can be changed into a prime (261305612047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 98978079 + ... + 98980718.

It is an arithmetic number, because the mean of its divisors is an integer number (13362218865).

Almost surely, 2^261305612040 is an apocalyptic number.

261305612040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261305612040 is an abundant number, since it is smaller than the sum of its proper divisors (593876395320).

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

261305612040 is a wasteful number, since it uses less digits than its factorization.

261305612040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197958822 (or 197958818 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 30.

The spelling of 261305612040 in words is "two hundred sixty-one billion, three hundred five million, six hundred twelve thousand, forty".