66886421 has 6 divisors (see below), whose sum is σ = 77806710. Its totient is φ = 57331176.

The previous prime is 66886411. The next prime is 66886429. The reversal of 66886421 is 12468866.

It can be written as a sum of positive squares in only one way, i.e., 54538225 + 12348196 = 7385^2 + 3514^2 .

It is not a de Polignac number, because 66886421 - 2⁶ = 66886357 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 (66886429) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 682466 + ... + 682563.

It is an arithmetic number, because the mean of its divisors is an integer number (12967785).

Almost surely, 2^66886421 is an apocalyptic number.

It is an amenable number.

66886421 is a deficient number, since it is larger than the sum of its proper divisors (10920289).

66886421 is a wasteful number, since it uses less digits than its factorization.

66886421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1365043 (or 1365036 counting only the distinct ones).

The product of its digits is 110592, while the sum is 41.

The square root of 66886421 is about 8178.4118874021. The cubic root of 66886421 is about 405.9251744785.

The spelling of 66886421 in words is "sixty-six million, eight hundred eighty-six thousand, four hundred twenty-one".