10209027821 has 4 divisors (see below), whose sum is σ = 10212827100. Its totient is φ = 10205228544.

The previous prime is 10209027811. The next prime is 10209027859. The reversal of 10209027821 is 12872090201.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 12872090201 = 419 ⋅30720979.

It can be written as a sum of positive squares in 2 ways, for example, as 2188929796 + 8020098025 = 46786^2 + 89555^2 .

It is a cyclic number.

It is not a de Polignac number, because 10209027821 - 2¹⁰ = 10209026797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10209027811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1895606 + ... + 1900983.

It is an arithmetic number, because the mean of its divisors is an integer number (2553206775).

Almost surely, 2^10209027821 is an apocalyptic number.

It is an amenable number.

10209027821 is a deficient number, since it is larger than the sum of its proper divisors (3799279).

10209027821 is an equidigital number, since it uses as much as digits as its factorization.

10209027821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3799278.

The product of its (nonzero) digits is 4032, while the sum is 32.

The spelling of 10209027821 in words is "ten billion, two hundred nine million, twenty-seven thousand, eight hundred twenty-one".