66833820 has 36 divisors (see below), whose sum is σ = 202729800. Its totient is φ = 17822304.

The previous prime is 66833807. The next prime is 66833827. The reversal of 66833820 is 2833866.

It is a tau number, because it is divible by the number of its divisors (36).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66833827) 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, 185470 + ... + 185829.

Almost surely, 2^66833820 is an apocalyptic number.

66833820 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66833820 is an abundant number, since it is smaller than the sum of its proper divisors (135895980).

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

66833820 is a wasteful number, since it uses less digits than its factorization.

66833820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 371314 (or 371309 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 66833820 is about 8175.1954105085. The cubic root of 66833820 is about 405.8187369810.

The spelling of 66833820 in words is "sixty-six million, eight hundred thirty-three thousand, eight hundred twenty".