287791861 has 16 divisors (see below), whose sum is σ = 350611200. Its totient is φ = 230595840.

The previous prime is 287791859. The next prime is 287791873. The reversal of 287791861 is 168197782.

It is a cyclic number.

It is not a de Polignac number, because 287791861 - 2¹ = 287791859 is a prime.

It is a super-3 number, since 3×287791861³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (287791891) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9616 + ... + 25846.

It is an arithmetic number, because the mean of its divisors is an integer number (21913200).

Almost surely, 2^287791861 is an apocalyptic number.

It is an amenable number.

287791861 is a deficient number, since it is larger than the sum of its proper divisors (62819339).

287791861 is a wasteful number, since it uses less digits than its factorization.

287791861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16404.

The product of its digits is 338688, while the sum is 49.

The square root of 287791861 is about 16964.4292860090. The cubic root of 287791861 is about 660.2263235141.

The spelling of 287791861 in words is "two hundred eighty-seven million, seven hundred ninety-one thousand, eight hundred sixty-one".