1666220722051 has 2 divisors, whose sum is σ = 1666220722052. Its totient is φ = 1666220722050.

The previous prime is 1666220722009. The next prime is 1666220722057. The reversal of 1666220722051 is 1502270226661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1666220722051 - 2²¹ = 1666218624899 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1666220721995 and 1666220722013.

It is not a weakly prime, because it can be changed into another prime (1666220722057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 833110361025 + 833110361026.

It is an arithmetic number, because the mean of its divisors is an integer number (833110361026).

Almost surely, 2^{1666220722051} is an apocalyptic number.

1666220722051 is a deficient number, since it is larger than the sum of its proper divisors (1).

1666220722051 is an equidigital number, since it uses as much as digits as its factorization.

1666220722051 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 40.

The spelling of 1666220722051 in words is "one trillion, six hundred sixty-six billion, two hundred twenty million, seven hundred twenty-two thousand, fifty-one".