66851900 has 36 divisors (see below), whose sum is σ = 146527080. Its totient is φ = 26472000.

The previous prime is 66851893. The next prime is 66851909. The reversal of 66851900 is 915866.

It is a super-2 number, since 2×66851900² = 8938353067220000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66851909) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6791 + ... + 13409.

Almost surely, 2^66851900 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66851900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (73263540).

66851900 is an abundant number, since it is smaller than the sum of its proper divisors (79675180).

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

66851900 is a wasteful number, since it uses less digits than its factorization.

66851900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6734 (or 6727 counting only the distinct ones).

The product of its (nonzero) digits is 12960, while the sum is 35.

The square root of 66851900 is about 8176.3011196995. The cubic root of 66851900 is about 405.8553279427.

The spelling of 66851900 in words is "sixty-six million, eight hundred fifty-one thousand, nine hundred".