261431023 has 12 divisors (see below), whose sum is σ = 304405992. Its totient is φ = 223868400.

The previous prime is 261430991. The next prime is 261431039. The reversal of 261431023 is 320134162.

It is not a de Polignac number, because 261431023 - 2⁵ = 261430991 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261430985 and 261431003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261431063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 69261 + ... + 72937.

It is an arithmetic number, because the mean of its divisors is an integer number (25367166).

Almost surely, 2^261431023 is an apocalyptic number.

261431023 is a deficient number, since it is larger than the sum of its proper divisors (42974969).

261431023 is a wasteful number, since it uses less digits than its factorization.

261431023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5142 (or 5135 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 22.

The square root of 261431023 is about 16168.8287454596. The cubic root of 261431023 is about 639.4192510080.

Adding to 261431023 its reverse (320134162), we get a palindrome (581565185).

The spelling of 261431023 in words is "two hundred sixty-one million, four hundred thirty-one thousand, twenty-three".