66551771 has 16 divisors (see below), whose sum is σ = 78475488. Its totient is φ = 55641600.

The previous prime is 66551747. The next prime is 66551777. The reversal of 66551771 is 17715566.

It is a cyclic number.

It is not a de Polignac number, because 66551771 - 2¹⁴ = 66535387 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66551777) 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, 47501 + ... + 48881.

It is an arithmetic number, because the mean of its divisors is an integer number (4904718).

Almost surely, 2^66551771 is an apocalyptic number.

66551771 is a deficient number, since it is larger than the sum of its proper divisors (11923717).

66551771 is a wasteful number, since it uses less digits than its factorization.

66551771 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1742.

The product of its digits is 44100, while the sum is 38.

The square root of 66551771 is about 8157.9268812609. The cubic root of 66551771 is about 405.2470595402.

The spelling of 66551771 in words is "sixty-six million, five hundred fifty-one thousand, seven hundred seventy-one".