21566670701651 has 2 divisors, whose sum is σ = 21566670701652. Its totient is φ = 21566670701650.

The previous prime is 21566670701603. The next prime is 21566670701689. The reversal of 21566670701651 is 15610707666512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21566670701651 - 2⁴² = 17168624190547 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21566670701593 and 21566670701602.

It is not a weakly prime, because it can be changed into another prime (21566670701351) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10783335350825 + 10783335350826.

It is an arithmetic number, because the mean of its divisors is an integer number (10783335350826).

Almost surely, 2^{21566670701651} is an apocalyptic number.

21566670701651 is a deficient number, since it is larger than the sum of its proper divisors (1).

21566670701651 is an equidigital number, since it uses as much as digits as its factorization.

21566670701651 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3175200, while the sum is 53.

The spelling of 21566670701651 in words is "twenty-one trillion, five hundred sixty-six billion, six hundred seventy million, seven hundred one thousand, six hundred fifty-one".