10122781 has 4 divisors (see below), whose sum is σ = 10129212. Its totient is φ = 10116352.

The previous prime is 10122773. The next prime is 10122797. The reversal of 10122781 is 18722101.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 8820900 + 1301881 = 2970^2 + 1141^2 .

It is a cyclic number.

It is not a de Polignac number, because 10122781 - 2³ = 10122773 is a prime.

It is a super-2 number, since 2×10122781² = 204941390347922, 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 (10122751) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 915 + ... + 4591.

It is an arithmetic number, because the mean of its divisors is an integer number (2532303).

Almost surely, 2^10122781 is an apocalyptic number.

It is an amenable number.

10122781 is a deficient number, since it is larger than the sum of its proper divisors (6431).

10122781 is an equidigital number, since it uses as much as digits as its factorization.

10122781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6430.

The product of its (nonzero) digits is 224, while the sum is 22.

The square root of 10122781 is about 3181.6318140225. The cubic root of 10122781 is about 216.3216301850.

Adding to 10122781 its reverse (18722101), we get a palindrome (28844882).

The spelling of 10122781 in words is "ten million, one hundred twenty-two thousand, seven hundred eighty-one".