66935821 has 8 divisors (see below), whose sum is σ = 70164864. Its totient is φ = 63782880.

The previous prime is 66935807. The next prime is 66935837. The reversal of 66935821 is 12853966.

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

It is a de Polignac number, because none of the positive numbers 2^k-66935821 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 (66935801) 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, 17221 + ... + 20746.

It is an arithmetic number, because the mean of its divisors is an integer number (8770608).

Almost surely, 2^66935821 is an apocalyptic number.

It is an amenable number.

66935821 is a deficient number, since it is larger than the sum of its proper divisors (3229043).

66935821 is a wasteful number, since it uses less digits than its factorization.

66935821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38051.

The product of its digits is 77760, while the sum is 40.

The square root of 66935821 is about 8181.4314762149. The cubic root of 66935821 is about 406.0250839898.

The spelling of 66935821 in words is "sixty-six million, nine hundred thirty-five thousand, eight hundred twenty-one".