261531023 has 8 divisors (see below), whose sum is σ = 282541728. Its totient is φ = 240647904.

The previous prime is 261530981. The next prime is 261531037. The reversal of 261531023 is 320135162.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 261531023 - 2⁸ = 261530767 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261531023.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261531073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27611 + ... + 35852.

It is an arithmetic number, because the mean of its divisors is an integer number (35317716).

Almost surely, 2^261531023 is an apocalyptic number.

261531023 is a deficient number, since it is larger than the sum of its proper divisors (21010705).

261531023 is a wasteful number, since it uses less digits than its factorization.

261531023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63793.

The product of its (nonzero) digits is 1080, while the sum is 23.

The square root of 261531023 is about 16171.9208197419. The cubic root of 261531023 is about 639.5007687168.

Adding to 261531023 its reverse (320135162), we get a palindrome (581666185).

The spelling of 261531023 in words is "two hundred sixty-one million, five hundred thirty-one thousand, twenty-three".