21056513545606 has 32 divisors (see below), whose sum is σ = 39466117555200. Its totient is φ = 8185565068800.

The previous prime is 21056513545591. The next prime is 21056513545607. The reversal of 21056513545606 is 60654531565012.

It is a happy number.

It is a super-2 number, since 2×21056513545606² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21056513545606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21056513545607) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 152192110 + ... + 152330401.

It is an arithmetic number, because the mean of its divisors is an integer number (1233316173600).

Almost surely, 2^{21056513545606} is an apocalyptic number.

21056513545606 is a deficient number, since it is larger than the sum of its proper divisors (18409604009594).

21056513545606 is a wasteful number, since it uses less digits than its factorization.

21056513545606 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 304522980.

The product of its (nonzero) digits is 3240000, while the sum is 49.

The spelling of 21056513545606 in words is "twenty-one trillion, fifty-six billion, five hundred thirteen million, five hundred forty-five thousand, six hundred six".