261561027 has 32 divisors (see below), whose sum is σ = 430133760. Its totient is φ = 137675520.

The previous prime is 261560993. The next prime is 261561059. The reversal of 261561027 is 720165162.

It is not a de Polignac number, because 261561027 - 2¹⁵ = 261528259 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 261560985 and 261561003.

It is not an unprimeable number, because it can be changed into a prime (261561067) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 207124 + ... + 208382.

It is an arithmetic number, because the mean of its divisors is an integer number (13441680).

Almost surely, 2^261561027 is an apocalyptic number.

261561027 is a deficient number, since it is larger than the sum of its proper divisors (168572733).

261561027 is a wasteful number, since it uses less digits than its factorization.

261561027 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2043.

The product of its (nonzero) digits is 5040, while the sum is 30.

The square root of 261561027 is about 16172.8484504122. The cubic root of 261561027 is about 639.5252232374.

The spelling of 261561027 in words is "two hundred sixty-one million, five hundred sixty-one thousand, twenty-seven".