166015231552661 has 2 divisors, whose sum is σ = 166015231552662. Its totient is φ = 166015231552660.

The previous prime is 166015231552477. The next prime is 166015231552669. The reversal of 166015231552661 is 166255132510661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 111643927336561 + 54371304216100 = 10566169^2 + 7373690^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-166015231552661 is a prime.

It is a super-3 number, since 3×166015231552661³ (a number of 44 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (166015231552669) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 83007615776330 + 83007615776331.

It is an arithmetic number, because the mean of its divisors is an integer number (83007615776331).

Almost surely, 2^{166015231552661} is an apocalyptic number.

It is an amenable number.

166015231552661 is a deficient number, since it is larger than the sum of its proper divisors (1).

166015231552661 is an equidigital number, since it uses as much as digits as its factorization.

166015231552661 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944000, while the sum is 50.

The spelling of 166015231552661 in words is "one hundred sixty-six trillion, fifteen billion, two hundred thirty-one million, five hundred fifty-two thousand, six hundred sixty-one".