21566670701603 has 2 divisors, whose sum is σ = 21566670701604. Its totient is φ = 21566670701602.

The previous prime is 21566670701551. The next prime is 21566670701651. The reversal of 21566670701603 is 30610707666512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21566670701603 - 2¹⁰ = 21566670700579 is a prime.

It is not a weakly prime, because it can be changed into another prime (21566670901603) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10783335350801 + 10783335350802.

It is an arithmetic number, because the mean of its divisors is an integer number (10783335350802).

Almost surely, 2^{21566670701603} is an apocalyptic number.

21566670701603 is a deficient number, since it is larger than the sum of its proper divisors (1).

21566670701603 is an equidigital number, since it uses as much as digits as its factorization.

21566670701603 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1905120, while the sum is 50.

The spelling of 21566670701603 in words is "twenty-one trillion, five hundred sixty-six billion, six hundred seventy million, seven hundred one thousand, six hundred three".