261532031 has 4 divisors (see below), whose sum is σ = 261693432. Its totient is φ = 261370632.

The previous prime is 261532009. The next prime is 261532049. The reversal of 261532031 is 130235162.

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 261532031 - 2¹⁸ = 261269887 is a prime.

It is a super-2 number, since 2×261532031² = 136798006477969922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261531988 and 261532006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261532001) 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 3 ways as a sum of consecutive naturals, for example, 78245 + ... + 81518.

It is an arithmetic number, because the mean of its divisors is an integer number (65423358).

Almost surely, 2^261532031 is an apocalyptic number.

261532031 is a deficient number, since it is larger than the sum of its proper divisors (161401).

261532031 is a wasteful number, since it uses less digits than its factorization.

261532031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161400.

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

The square root of 261532031 is about 16171.9519848409. The cubic root of 261532031 is about 639.5015903095.

Adding to 261532031 its reverse (130235162), we get a palindrome (391767193).

The spelling of 261532031 in words is "two hundred sixty-one million, five hundred thirty-two thousand, thirty-one".