261111135021 has 16 divisors (see below), whose sum is σ = 379809458688. Its totient is φ = 158244404400.

The previous prime is 261111135007. The next prime is 261111135037. The reversal of 261111135021 is 120531111162.

It is not a de Polignac number, because 261111135021 - 2⁶ = 261111134957 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261111134982 and 261111135000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261111135121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1215666 + ... + 1414236.

It is an arithmetic number, because the mean of its divisors is an integer number (23738091168).

Almost surely, 2^261111135021 is an apocalyptic number.

It is an amenable number.

261111135021 is a deficient number, since it is larger than the sum of its proper divisors (118698323667).

261111135021 is a wasteful number, since it uses less digits than its factorization.

261111135021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238432.

The product of its (nonzero) digits is 360, while the sum is 24.

Adding to 261111135021 its reverse (120531111162), we get a palindrome (381642246183).

The spelling of 261111135021 in words is "two hundred sixty-one billion, one hundred eleven million, one hundred thirty-five thousand, twenty-one".