66555101 has 4 divisors (see below), whose sum is σ = 66765372. Its totient is φ = 66344832.

The previous prime is 66555089. The next prime is 66555103. The reversal of 66555101 is 10155566.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 10155566 = 2 ⋅5077783.

It can be written as a sum of positive squares in 2 ways, for example, as 4618201 + 61936900 = 2149^2 + 7870^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66555101 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66555103) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 104660 + ... + 105293.

It is an arithmetic number, because the mean of its divisors is an integer number (16691343).

Almost surely, 2^66555101 is an apocalyptic number.

It is an amenable number.

66555101 is a deficient number, since it is larger than the sum of its proper divisors (210271).

66555101 is a wasteful number, since it uses less digits than its factorization.

66555101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 210270.

The product of its (nonzero) digits is 4500, while the sum is 29.

The square root of 66555101 is about 8158.1309746780. The cubic root of 66555101 is about 405.2538184397.

The spelling of 66555101 in words is "sixty-six million, five hundred fifty-five thousand, one hundred one".