21145646435013 has 12 divisors (see below), whose sum is σ = 31596942949260. Its totient is φ = 13610990808576.

The previous prime is 21145646434999. The next prime is 21145646435021. The reversal of 21145646435013 is 31053464654112.

21145646435013 is a `hidden beast` number, since 2 + 1 + 1 + 45 + 64 + 6 + 43 + 501 + 3 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 15639311987649 + 5506334447364 = 3954657^2 + 2346558^2 .

It is not a de Polignac number, because 21145646435013 - 2²⁹ = 21145109564101 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21145646435013.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21145646435083) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40508900956 + ... + 40508901477.

It is an arithmetic number, because the mean of its divisors is an integer number (2633078579105).

Almost surely, 2^{21145646435013} is an apocalyptic number.

It is an amenable number.

21145646435013 is a deficient number, since it is larger than the sum of its proper divisors (10451296514247).

21145646435013 is a wasteful number, since it uses less digits than its factorization.

21145646435013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 81017802468 (or 81017802465 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 45.

The spelling of 21145646435013 in words is "twenty-one trillion, one hundred forty-five billion, six hundred forty-six million, four hundred thirty-five thousand, thirteen".