20566851217403 has 16 divisors (see below), whose sum is σ = 21172112881920. Its totient is φ = 19967371329696.

The previous prime is 20566851217399. The next prime is 20566851217441. The reversal of 20566851217403 is 30471215866502.

It is a cyclic number.

It is not a de Polignac number, because 20566851217403 - 2² = 20566851217399 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20566851217303) 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, 208393553 + ... + 208492221.

It is an arithmetic number, because the mean of its divisors is an integer number (1323257055120).

Almost surely, 2^{20566851217403} is an apocalyptic number.

20566851217403 is a deficient number, since it is larger than the sum of its proper divisors (605261664517).

20566851217403 is a wasteful number, since it uses less digits than its factorization.

20566851217403 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127906.

The product of its (nonzero) digits is 2419200, while the sum is 50.

The spelling of 20566851217403 in words is "twenty trillion, five hundred sixty-six billion, eight hundred fifty-one million, two hundred seventeen thousand, four hundred three".