261011121556134 has 16 divisors (see below), whose sum is σ = 528630119608320. Its totient is φ = 85902394436040.

The previous prime is 261011121556127. The next prime is 261011121556147. The reversal of 261011121556134 is 431655121110162.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 261011121556092 and 261011121556101.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 275328186822 + ... + 275328187769.

It is an arithmetic number, because the mean of its divisors is an integer number (33039382475520).

Almost surely, 2^{261011121556134} is an apocalyptic number.

261011121556134 is an abundant number, since it is smaller than the sum of its proper divisors (267618998052186).

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

261011121556134 is a wasteful number, since it uses less digits than its factorization.

261011121556134 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 550656374675.

The product of its (nonzero) digits is 43200, while the sum is 39.

Adding to 261011121556134 its reverse (431655121110162), we get a palindrome (692666242666296).

The spelling of 261011121556134 in words is "two hundred sixty-one trillion, eleven billion, one hundred twenty-one million, five hundred fifty-six thousand, one hundred thirty-four".