687500281 has 12 divisors (see below), whose sum is σ = 788247612. Its totient is φ = 597282816.

The previous prime is 687500267. The next prime is 687500309. The reversal of 687500281 is 182005786.

687500281 = 18540² + 18541².

It can be written as a sum of positive squares in 6 ways, for example, as 11881 + 687488400 = 109^2 + 26220^2 .

It is not a de Polignac number, because 687500281 - 2¹⁵ = 687467513 is a prime.

It is a super-2 number, since 2×687500281² = 945313272750157922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 687500281.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (687500201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 116776 + ... + 122521.

It is an arithmetic number, because the mean of its divisors is an integer number (65687301).

Almost surely, 2^687500281 is an apocalyptic number.

687500281 is the 18541-st centered square number.

It is an amenable number.

687500281 is a deficient number, since it is larger than the sum of its proper divisors (100747331).

687500281 is a wasteful number, since it uses less digits than its factorization.

687500281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239340 (or 239327 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 37.

The square root of 687500281 is about 26220.2265627130. The cubic root of 687500281 is about 882.5872040773.

The spelling of 687500281 in words is "six hundred eighty-seven million, five hundred thousand, two hundred eighty-one".