287932261 has 16 divisors (see below), whose sum is σ = 302576368. Its totient is φ = 273715200.

The previous prime is 287932259. The next prime is 287932273. The reversal of 287932261 is 162239782.

It can be written as a sum of positive squares in 8 ways, for example, as 799236 + 287133025 = 894^2 + 16945^2 .

It is a 6-Lehmer number, since φ(287932261) divides (287932261-1)⁶.

It is a cyclic number.

It is not a de Polignac number, because 287932261 - 2¹ = 287932259 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (287932201) by changing a digit.

It is a nontrivial repunit in base 660.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 435271 + ... + 435931.

It is an arithmetic number, because the mean of its divisors is an integer number (18911023).

Almost surely, 2^287932261 is an apocalyptic number.

It is an amenable number.

287932261 is a deficient number, since it is larger than the sum of its proper divisors (14644107).

287932261 is a wasteful number, since it uses less digits than its factorization.

287932261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 952.

The product of its digits is 72576, while the sum is 40.

The square root of 287932261 is about 16968.5668516820. The cubic root of 287932261 is about 660.3336704298. Note that the first 3 decimals are identical.

The spelling of 287932261 in words is "two hundred eighty-seven million, nine hundred thirty-two thousand, two hundred sixty-one".