66856061 has 8 divisors (see below), whose sum is σ = 68593824. Its totient is φ = 65139120.

The previous prime is 66856039. The next prime is 66856073. The reversal of 66856061 is 16065866.

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 66856061 - 2¹⁰ = 66855037 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 (66856001) 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, 1406 + ... + 11648.

It is an arithmetic number, because the mean of its divisors is an integer number (8574228).

Almost surely, 2^66856061 is an apocalyptic number.

66856061 is a gapful number since it is divisible by the number (61) formed by its first and last digit.

It is an amenable number.

66856061 is a deficient number, since it is larger than the sum of its proper divisors (1737763).

66856061 is a wasteful number, since it uses less digits than its factorization.

66856061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10411.

The product of its (nonzero) digits is 51840, while the sum is 38.

The square root of 66856061 is about 8176.5555706544. Note that the first 4 decimals coincide. The cubic root of 66856061 is about 405.8637481919.

The spelling of 66856061 in words is "sixty-six million, eight hundred fifty-six thousand, sixty-one".