261290 has 32 divisors (see below), whose sum is σ = 524880. Its totient is φ = 93184.

The previous prime is 261281. The next prime is 261301. The reversal of 261290 is 92162.

It can be written as a sum of positive squares in 8 ways, for example, as 182329 + 78961 = 427^2 + 281^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4904 + ... + 4956.

2²⁶¹²⁹⁰ is an apocalyptic number.

261290 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261290 is a wasteful number, since it uses less digits than its factorization.

261290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 106.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 261290 is about 511.1653352879. The cubic root of 261290 is about 63.9304256954.

The spelling of 261290 in words is "two hundred sixty-one thousand, two hundred ninety".