261344423431 has 32 divisors (see below), whose sum is σ = 324005068800. Its totient is φ = 205268701824.

The previous prime is 261344423413. The next prime is 261344423453. The reversal of 261344423431 is 134324443162.

It is a cyclic number.

It is not a de Polignac number, because 261344423431 - 2¹⁹ = 261343899143 is a prime.

It is a super-2 number, since 2×261344423431² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261344433431) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 27967546 + ... + 27976888.

It is an arithmetic number, because the mean of its divisors is an integer number (10125158400).

Almost surely, 2^261344423431 is an apocalyptic number.

261344423431 is a deficient number, since it is larger than the sum of its proper divisors (62660645369).

261344423431 is a wasteful number, since it uses less digits than its factorization.

261344423431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11575.

The product of its digits is 165888, while the sum is 37.

Adding to 261344423431 its reverse (134324443162), we get a palindrome (395668866593).

The spelling of 261344423431 in words is "two hundred sixty-one billion, three hundred forty-four million, four hundred twenty-three thousand, four hundred thirty-one".