65851866 has 80 divisors (see below), whose sum is σ = 155247840. Its totient is φ = 20835360.

The previous prime is 65851831. The next prime is 65851867. The reversal of 65851866 is 66815856.

65851866 is a `hidden beast` number, since 6 + 585 + 1 + 8 + 66 = 666.

It is not an unprimeable number, because it can be changed into a prime (65851867) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 502621 + ... + 502751.

It is an arithmetic number, because the mean of its divisors is an integer number (1940598).

Almost surely, 2^65851866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65851866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77623920).

65851866 is an abundant number, since it is smaller than the sum of its proper divisors (89395974).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

65851866 is a wasteful number, since it uses less digits than its factorization.

65851866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281 (or 272 counting only the distinct ones).

The product of its digits is 345600, while the sum is 45.

The square root of 65851866 is about 8114.9162657417. The cubic root of 65851866 is about 403.8214295947.

The spelling of 65851866 in words is "sixty-five million, eight hundred fifty-one thousand, eight hundred sixty-six".