261240142836 has 48 divisors (see below), whose sum is σ = 611049922560. Its totient is φ = 86867482080.

The previous prime is 261240142799. The next prime is 261240142843. The reversal of 261240142836 is 638241042162.

261240142836 is digitally balanced in base 7, because in such base it contains all the possibile digits an equal number of times.

It is a junction number, because it is equal to n+sod(n) for n = 261240142794 and 261240142803.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9594001 + ... + 9621191.

It is an arithmetic number, because the mean of its divisors is an integer number (12730206720).

Almost surely, 2^261240142836 is an apocalyptic number.

It is an amenable number.

261240142836 is an abundant number, since it is smaller than the sum of its proper divisors (349809779724).

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

261240142836 is a wasteful number, since it uses less digits than its factorization.

261240142836 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29124 (or 29122 counting only the distinct ones).

The product of its (nonzero) digits is 110592, while the sum is 39.

Adding to 261240142836 its reverse (638241042162), we get a palindrome (899481184998).

The spelling of 261240142836 in words is "two hundred sixty-one billion, two hundred forty million, one hundred forty-two thousand, eight hundred thirty-six".