21606251526610 has 64 divisors (see below), whose sum is σ = 40399707160800. Its totient is φ = 8309840136192.

The previous prime is 21606251526577. The next prime is 21606251526611. The reversal of 21606251526610 is 1662515260612.

It can be written as a sum of positive squares in 16 ways, for example, as 5623390934161 + 15982860592449 = 2371369^2 + 3997857^2 .

It is a super-2 number, since 2×21606251526610² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21606251526611) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 67297624 + ... + 67617916.

Almost surely, 2^{21606251526610} is an apocalyptic number.

21606251526610 is a deficient number, since it is larger than the sum of its proper divisors (18793455634190).

21606251526610 is a wasteful number, since it uses less digits than its factorization.

21606251526610 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321295.

The product of its (nonzero) digits is 259200, while the sum is 43.

The spelling of 21606251526610 in words is "twenty-one trillion, six hundred six billion, two hundred fifty-one million, five hundred twenty-six thousand, six hundred ten".