21206043610 has 16 divisors (see below), whose sum is σ = 40416224616. Its totient is φ = 7983451648.

The previous prime is 21206043589. The next prime is 21206043611. The reversal of 21206043610 is 1634060212.

It can be written as a sum of positive squares in 4 ways, for example, as 12263126121 + 8942917489 = 110739^2 + 94567^2 .

It is not an unprimeable number, because it can be changed into a prime (21206043611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 62370547 + ... + 62370886.

Almost surely, 2^21206043610 is an apocalyptic number.

21206043610 is a deficient number, since it is larger than the sum of its proper divisors (19210181006).

21206043610 is a wasteful number, since it uses less digits than its factorization.

21206043610 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124741457.

The product of its (nonzero) digits is 1728, while the sum is 25.

The spelling of 21206043610 in words is "twenty-one billion, two hundred six million, forty-three thousand, six hundred ten".