261143023 has 4 divisors (see below), whose sum is σ = 263583720. Its totient is φ = 258702328.

The previous prime is 261143017. The next prime is 261143033. The reversal of 261143023 is 320341162.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 261143023 - 2⁵ = 261142991 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261142985 and 261143003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261143033) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1220188 + ... + 1220401.

It is an arithmetic number, because the mean of its divisors is an integer number (65895930).

Almost surely, 2^261143023 is an apocalyptic number.

261143023 is a deficient number, since it is larger than the sum of its proper divisors (2440697).

261143023 is a wasteful number, since it uses less digits than its factorization.

261143023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2440696.

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

The square root of 261143023 is about 16159.9202658924. The cubic root of 261143023 is about 639.1843638011.

Adding to 261143023 its reverse (320341162), we get a palindrome (581484185).

The spelling of 261143023 in words is "two hundred sixty-one million, one hundred forty-three thousand, twenty-three".