10687781 has 16 divisors (see below), whose sum is σ = 12310704. Its totient is φ = 9191424.

The previous prime is 10687727. The next prime is 10687811. The reversal of 10687781 is 18778601.

It can be written as a sum of positive squares in 8 ways, for example, as 27556 + 10660225 = 166^2 + 3265^2 .

It is not a de Polignac number, because 10687781 - 2¹⁸ = 10425637 is a prime.

It is a super-2 number, since 2×10687781² = 228457325407922, which contains 22 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 (10687081) 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, 30101 + ... + 30453.

It is an arithmetic number, because the mean of its divisors is an integer number (769419).

Almost surely, 2^10687781 is an apocalyptic number.

It is an amenable number.

10687781 is a deficient number, since it is larger than the sum of its proper divisors (1622923).

10687781 is a wasteful number, since it uses less digits than its factorization.

10687781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 520.

The product of its (nonzero) digits is 18816, while the sum is 38.

The square root of 10687781 is about 3269.2171845872. The cubic root of 10687781 is about 220.2736333462.

The spelling of 10687781 in words is "ten million, six hundred eighty-seven thousand, seven hundred eighty-one".