261506131 has 4 divisors (see below), whose sum is σ = 262089000. Its totient is φ = 260923264.

The previous prime is 261506129. The next prime is 261506183. The reversal of 261506131 is 131605162.

261506131 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 261506131 - 2¹ = 261506129 is a prime.

It is a super-2 number, since 2×261506131² = 136770913101178322, 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 = 261506096 and 261506105.

It is not an unprimeable number, because it can be changed into a prime (261500131) 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, 290761 + ... + 291658.

It is an arithmetic number, because the mean of its divisors is an integer number (65522250).

Almost surely, 2^261506131 is an apocalyptic number.

261506131 is a deficient number, since it is larger than the sum of its proper divisors (582869).

261506131 is an equidigital number, since it uses as much as digits as its factorization.

261506131 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 582868.

The product of its (nonzero) digits is 1080, while the sum is 25.

The square root of 261506131 is about 16171.1511958797. The cubic root of 261506131 is about 639.4804792715.

The spelling of 261506131 in words is "two hundred sixty-one million, five hundred six thousand, one hundred thirty-one".