166021027332401 has 2 divisors, whose sum is σ = 166021027332402. Its totient is φ = 166021027332400.

The previous prime is 166021027332383. The next prime is 166021027332409. The reversal of 166021027332401 is 104233720120661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 160293932204176 + 5727095128225 = 12660724^2 + 2393135^2 .

It is an emirp because it is prime and its reverse (104233720120661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 166021027332401 - 2²² = 166021023138097 is a prime.

It is a super-3 number, since 3×166021027332401³ (a number of 44 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (166021027332409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83010513666200 + 83010513666201.

It is an arithmetic number, because the mean of its divisors is an integer number (83010513666201).

Almost surely, 2^{166021027332401} is an apocalyptic number.

It is an amenable number.

166021027332401 is a deficient number, since it is larger than the sum of its proper divisors (1).

166021027332401 is an equidigital number, since it uses as much as digits as its factorization.

166021027332401 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72576, while the sum is 38.

The spelling of 166021027332401 in words is "one hundred sixty-six trillion, twenty-one billion, twenty-seven million, three hundred thirty-two thousand, four hundred one".