66354821 has 8 divisors (see below), whose sum is σ = 75220320. Its totient is φ = 58026672.

The previous prime is 66354817. The next prime is 66354823. The reversal of 66354821 is 12845366.

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

It is a cyclic number.

It is not a de Polignac number, because 66354821 - 2² = 66354817 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 (66354823) 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, 134075 + ... + 134568.

It is an arithmetic number, because the mean of its divisors is an integer number (9402540).

Almost surely, 2^66354821 is an apocalyptic number.

It is an amenable number.

66354821 is a deficient number, since it is larger than the sum of its proper divisors (8865499).

66354821 is a wasteful number, since it uses less digits than its factorization.

66354821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268675.

The product of its digits is 34560, while the sum is 35.

The square root of 66354821 is about 8145.8468559138. The cubic root of 66354821 is about 404.8469085559.

The spelling of 66354821 in words is "sixty-six million, three hundred fifty-four thousand, eight hundred twenty-one".