166021562105831 has 2 divisors, whose sum is σ = 166021562105832. Its totient is φ = 166021562105830.

The previous prime is 166021562105827. The next prime is 166021562105851. The reversal of 166021562105831 is 138501265120661.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 166021562105831 - 2² = 166021562105827 is a prime.

It is a super-2 number, since 2×166021562105831² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166021562105851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83010781052915 + 83010781052916.

It is an arithmetic number, because the mean of its divisors is an integer number (83010781052916).

Almost surely, 2^{166021562105831} is an apocalyptic number.

166021562105831 is a deficient number, since it is larger than the sum of its proper divisors (1).

166021562105831 is an equidigital number, since it uses as much as digits as its factorization.

166021562105831 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 518400, while the sum is 47.

The spelling of 166021562105831 in words is "one hundred sixty-six trillion, twenty-one billion, five hundred sixty-two million, one hundred five thousand, eight hundred thirty-one".