66871421 has 12 divisors (see below), whose sum is σ = 72059040. Its totient is φ = 62032320.

The previous prime is 66871381. The next prime is 66871463. The reversal of 66871421 is 12417866.

It is not a de Polignac number, because 66871421 - 2¹⁴ = 66855037 is a prime.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66870421) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18890 + ... + 22148.

It is an arithmetic number, because the mean of its divisors is an integer number (6004920).

Almost surely, 2^66871421 is an apocalyptic number.

It is an amenable number.

66871421 is a deficient number, since it is larger than the sum of its proper divisors (5187619).

66871421 is a wasteful number, since it uses less digits than its factorization.

66871421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3364 (or 3347 counting only the distinct ones).

The product of its digits is 16128, while the sum is 35.

The square root of 66871421 is about 8177.4947875251. The cubic root of 66871421 is about 405.8948278464.

The spelling of 66871421 in words is "sixty-six million, eight hundred seventy-one thousand, four hundred twenty-one".