21656603020210 has 128 divisors (see below), whose sum is σ = 42829710336000. Its totient is φ = 7852703459328.

The previous prime is 21656603020079. The next prime is 21656603020243. The reversal of 21656603020210 is 1202030665612.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 655667976 + ... + 655701004.

It is an arithmetic number, because the mean of its divisors is an integer number (334607112000).

Almost surely, 2^{21656603020210} is an apocalyptic number.

21656603020210 is a deficient number, since it is larger than the sum of its proper divisors (21173107315790).

21656603020210 is a wasteful number, since it uses less digits than its factorization.

21656603020210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34148.

The product of its (nonzero) digits is 25920, while the sum is 34.

Adding to 21656603020210 its reverse (1202030665612), we get a palindrome (22858633685822).

The spelling of 21656603020210 in words is "twenty-one trillion, six hundred fifty-six billion, six hundred three million, twenty thousand, two hundred ten".