66542971 has 8 divisors (see below), whose sum is σ = 72802224. Its totient is φ = 60318720.

The previous prime is 66542951. The next prime is 66543011. The reversal of 66542971 is 17924566.

66542971 = T₄₂₉ + T₄₃₀ + ... + T₇₈₁.

66542971 is nontrivially palindromic in base 8.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 66542971 - 2⁵ = 66542939 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66542911) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4686 + ... + 12451.

It is an arithmetic number, because the mean of its divisors is an integer number (9100278).

Almost surely, 2^66542971 is an apocalyptic number.

66542971 is a deficient number, since it is larger than the sum of its proper divisors (6259253).

66542971 is a wasteful number, since it uses less digits than its factorization.

66542971 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17501.

The product of its digits is 90720, while the sum is 40.

The square root of 66542971 is about 8157.3875107169. The cubic root of 66542971 is about 405.2291970989.

The spelling of 66542971 in words is "sixty-six million, five hundred forty-two thousand, nine hundred seventy-one".