10987821 has 12 divisors (see below), whose sum is σ = 17092348. Its totient is φ = 6761664.

The previous prime is 10987819. The next prime is 10987829. The reversal of 10987821 is 12878901.

It can be written as a sum of positive squares in 2 ways, for example, as 4284900 + 6702921 = 2070^2 + 2589^2 .

It is not a de Polignac number, because 10987821 - 2¹ = 10987819 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (10987829) 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 11 ways as a sum of consecutive naturals, for example, 46840 + ... + 47073.

Almost surely, 2^10987821 is an apocalyptic number.

It is an amenable number.

10987821 is a deficient number, since it is larger than the sum of its proper divisors (6104527).

10987821 is a wasteful number, since it uses less digits than its factorization.

10987821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93932 (or 93929 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 10987821 is about 3314.7882285298. The cubic root of 10987821 is about 222.3159004024.

The spelling of 10987821 in words is "ten million, nine hundred eighty-seven thousand, eight hundred twenty-one".