65881664 has 56 divisors (see below), whose sum is σ = 145755360. Its totient is φ = 29362176.

The previous prime is 65881661. The next prime is 65881709. The reversal of 65881664 is 46618856.

It is not an unprimeable number, because it can be changed into a prime (65881661) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19079 + ... + 22265.

Almost surely, 2^65881664 is an apocalyptic number.

65881664 is a gapful number since it is divisible by the number (64) 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 65881664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (72877680).

65881664 is an abundant number, since it is smaller than the sum of its proper divisors (79873696).

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

65881664 is a wasteful number, since it uses less digits than its factorization.

65881664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3235 (or 3225 counting only the distinct ones).

The product of its digits is 276480, while the sum is 44.

The square root of 65881664 is about 8116.7520597835. The cubic root of 65881664 is about 403.8823302047.

The spelling of 65881664 in words is "sixty-five million, eight hundred eighty-one thousand, six hundred sixty-four".