261138023 has 4 divisors (see below), whose sum is σ = 261170520. Its totient is φ = 261105528.

The previous prime is 261138013. The next prime is 261138043. The reversal of 261138023 is 320831162.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 261138023 - 2⁶ = 261137959 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261137983 and 261138001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261138013) 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, 5588 + ... + 23526.

It is an arithmetic number, because the mean of its divisors is an integer number (65292630).

Almost surely, 2^261138023 is an apocalyptic number.

261138023 is a deficient number, since it is larger than the sum of its proper divisors (32497).

261138023 is a wasteful number, since it uses less digits than its factorization.

261138023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32496.

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 261138023 is about 16159.7655614183. The cubic root of 261138023 is about 639.1802843734.

Adding to 261138023 its reverse (320831162), we get a palindrome (581969185).

The spelling of 261138023 in words is "two hundred sixty-one million, one hundred thirty-eight thousand, twenty-three".