21126656540410 has 16 divisors (see below), whose sum is σ = 38651391311112. Its totient is φ = 8312127163200.

The previous prime is 21126656540399. The next prime is 21126656540453. The reversal of 21126656540410 is 1404565662112.

It can be written as a sum of positive squares in 4 ways, for example, as 13163915060521 + 7962741479889 = 3628211^2 + 2821833^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17316930981 + ... + 17316932200.

Almost surely, 2^{21126656540410} is an apocalyptic number.

21126656540410 is a deficient number, since it is larger than the sum of its proper divisors (17524734770702).

21126656540410 is a wasteful number, since it uses less digits than its factorization.

21126656540410 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34633863249.

The product of its (nonzero) digits is 345600, while the sum is 43.

The spelling of 21126656540410 in words is "twenty-one trillion, one hundred twenty-six billion, six hundred fifty-six million, five hundred forty thousand, four hundred ten".