21361012 has 6 divisors (see below), whose sum is σ = 37381778. Its totient is φ = 10680504.

The previous prime is 21361003. The next prime is 21361013. The reversal of 21361012 is 21016312.

It can be written as a sum of positive squares in only one way, i.e., 20848356 + 512656 = 4566^2 + 716^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21361013) 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 as a sum of consecutive naturals, namely, 2670123 + ... + 2670130.

Almost surely, 2^21361012 is an apocalyptic number.

It is an amenable number.

21361012 is a deficient number, since it is larger than the sum of its proper divisors (16020766).

21361012 is a wasteful number, since it uses less digits than its factorization.

21361012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5340257 (or 5340255 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 21361012 is about 4621.7974858273. The cubic root of 21361012 is about 277.4644036260.

Adding to 21361012 its reverse (21016312), we get a palindrome (42377324).

The spelling of 21361012 in words is "twenty-one million, three hundred sixty-one thousand, twelve".