21661056206313 has 8 divisors (see below), whose sum is σ = 28881429772800. Its totient is φ = 14440693388688.

The previous prime is 21661056206269. The next prime is 21661056206329. The reversal of 21661056206313 is 31360265016612.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21661056206313 - 2¹⁰ = 21661056205289 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21661056206213) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6621103 + ... + 9336011.

It is an arithmetic number, because the mean of its divisors is an integer number (3610178721600).

Almost surely, 2^{21661056206313} is an apocalyptic number.

It is an amenable number.

21661056206313 is a deficient number, since it is larger than the sum of its proper divisors (7220373566487).

21661056206313 is a wasteful number, since it uses less digits than its factorization.

21661056206313 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5374431.

The product of its (nonzero) digits is 233280, while the sum is 42.

The spelling of 21661056206313 in words is "twenty-one trillion, six hundred sixty-one billion, fifty-six million, two hundred six thousand, three hundred thirteen".