65667720 has 64 divisors (see below), whose sum is σ = 200255040. Its totient is φ = 17222400.

The previous prime is 65667673. The next prime is 65667731. The reversal of 65667720 is 2776656.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2835 + ... + 11805.

It is an arithmetic number, because the mean of its divisors is an integer number (3128985).

Almost surely, 2^65667720 is an apocalyptic number.

65667720 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 65667720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100127520).

65667720 is an abundant number, since it is smaller than the sum of its proper divisors (134587320).

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

65667720 is a wasteful number, since it uses less digits than its factorization.

65667720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9046 (or 9042 counting only the distinct ones).

The product of its (nonzero) digits is 105840, while the sum is 39.

The square root of 65667720 is about 8103.5621796837. The cubic root of 65667720 is about 403.4446671835. Note that the first 3 decimals are identical.

The spelling of 65667720 in words is "sixty-five million, six hundred sixty-seven thousand, seven hundred twenty".