66985620 has 96 divisors (see below), whose sum is σ = 203645568. Its totient is φ = 16353792.

The previous prime is 66985613. The next prime is 66985631. The reversal of 66985620 is 2658966.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 122187 + ... + 122733.

It is an arithmetic number, because the mean of its divisors is an integer number (2121308).

Almost surely, 2^66985620 is an apocalyptic number.

66985620 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66985620, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (101822784).

66985620 is an abundant number, since it is smaller than the sum of its proper divisors (136659948).

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

66985620 is a wasteful number, since it uses less digits than its factorization.

66985620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 729 (or 727 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 42.

The square root of 66985620 is about 8184.4743264305. The cubic root of 66985620 is about 406.1257507209.

The spelling of 66985620 in words is "sixty-six million, nine hundred eighty-five thousand, six hundred twenty".