10002781 has 4 divisors (see below), whose sum is σ = 10075932. Its totient is φ = 9929632.

The previous prime is 10002779. The next prime is 10002791. The reversal of 10002781 is 18720001.

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 6996025 + 3006756 = 2645^2 + 1734^2 .

It is a cyclic number.

It is not a de Polignac number, because 10002781 - 2¹ = 10002779 is a prime.

It is a super-2 number, since 2×10002781² = 200111255467922, 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 (10002731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36370 + ... + 36643.

It is an arithmetic number, because the mean of its divisors is an integer number (2518983).

Almost surely, 2^10002781 is an apocalyptic number.

It is an amenable number.

10002781 is a deficient number, since it is larger than the sum of its proper divisors (73151).

10002781 is an equidigital number, since it uses as much as digits as its factorization.

10002781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73150.

The product of its (nonzero) digits is 112, while the sum is 19.

The square root of 10002781 is about 3162.7173443101. The cubic root of 10002781 is about 215.4634387617.

Adding to 10002781 its reverse (18720001), we get a palindrome (28722782).

The spelling of 10002781 in words is "ten million, two thousand, seven hundred eighty-one".