166065506105551 has 16 divisors (see below), whose sum is σ = 188253431049600. Its totient is φ = 145222477807968.

The previous prime is 166065506105537. The next prime is 166065506105561. The reversal of 166065506105551 is 155501605560661.

It is a cyclic number.

It is not a de Polignac number, because 166065506105551 - 2¹⁵ = 166065506072783 is a prime.

It is a super-3 number, since 3×166065506105551³ (a number of 44 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166065506105501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45608340 + ... + 49114678.

It is an arithmetic number, because the mean of its divisors is an integer number (11765839440600).

Almost surely, 2^{166065506105551} is an apocalyptic number.

166065506105551 is a deficient number, since it is larger than the sum of its proper divisors (22187924944049).

166065506105551 is a wasteful number, since it uses less digits than its factorization.

166065506105551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3698118.

The product of its (nonzero) digits is 4050000, while the sum is 52.

The spelling of 166065506105551 in words is "one hundred sixty-six trillion, sixty-five billion, five hundred six million, one hundred five thousand, five hundred fifty-one".