261290273 has 4 divisors (see below), whose sum is σ = 261502740. Its totient is φ = 261077808.

The previous prime is 261290269. The next prime is 261290279. The reversal of 261290273 is 372092162.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 168688144 + 92602129 = 12988^2 + 9623^2 .

It is a cyclic number.

It is not a de Polignac number, because 261290273 - 2² = 261290269 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261290279) 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, 104378 + ... + 106851.

It is an arithmetic number, because the mean of its divisors is an integer number (65375685).

Almost surely, 2^261290273 is an apocalyptic number.

It is an amenable number.

261290273 is a deficient number, since it is larger than the sum of its proper divisors (212467).

261290273 is a wasteful number, since it uses less digits than its factorization.

261290273 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212466.

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 261290273 is about 16164.4756487800. The cubic root of 261290273 is about 639.3044796054.

The spelling of 261290273 in words is "two hundred sixty-one million, two hundred ninety thousand, two hundred seventy-three".