261075771 has 48 divisors (see below), whose sum is σ = 428685600. Its totient is φ = 156911040.

The previous prime is 261075761. The next prime is 261075781. The reversal of 261075771 is 177570162.

It is an interprime number because it is at equal distance from previous prime (261075761) and next prime (261075781).

It is not a de Polignac number, because 261075771 - 2⁵ = 261075739 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261075701) 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 47 ways as a sum of consecutive naturals, for example, 512665 + ... + 513173.

It is an arithmetic number, because the mean of its divisors is an integer number (8930950).

Almost surely, 2^261075771 is an apocalyptic number.

261075771 is a deficient number, since it is larger than the sum of its proper divisors (167609829).

261075771 is a wasteful number, since it uses less digits than its factorization.

261075771 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 697 (or 680 counting only the distinct ones).

The product of its (nonzero) digits is 20580, while the sum is 36.

The square root of 261075771 is about 16157.8393048081. The cubic root of 261075771 is about 639.1294895066.

It can be divided in two parts, 26107 and 5771, that added together give a triangular number (31878 = T₂₅₂).

The spelling of 261075771 in words is "two hundred sixty-one million, seventy-five thousand, seven hundred seventy-one".