261523154211 has 16 divisors (see below), whose sum is σ = 392668197888. Its totient is φ = 153386013600.

The previous prime is 261523154177. The next prime is 261523154231. The reversal of 261523154211 is 112451325162.

It is not a de Polignac number, because 261523154211 - 2¹⁵ = 261523121443 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (261523154231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 127820656 + ... + 127822701.

It is an arithmetic number, because the mean of its divisors is an integer number (24541762368).

Almost surely, 2^261523154211 is an apocalyptic number.

261523154211 is a deficient number, since it is larger than the sum of its proper divisors (131145043677).

261523154211 is a wasteful number, since it uses less digits than its factorization.

261523154211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 255643402.

The product of its digits is 14400, while the sum is 33.

Adding to 261523154211 its reverse (112451325162), we get a palindrome (373974479373).

The spelling of 261523154211 in words is "two hundred sixty-one billion, five hundred twenty-three million, one hundred fifty-four thousand, two hundred eleven".