65721366 has 48 divisors (see below), whose sum is σ = 148543200. Its totient is φ = 20974464.

The previous prime is 65721353. The next prime is 65721379. The reversal of 65721366 is 66312756.

It is an interprime number because it is at equal distance from previous prime (65721353) and next prime (65721379).

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 65721366.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 71055 + ... + 71973.

It is an arithmetic number, because the mean of its divisors is an integer number (3094650).

Almost surely, 2^65721366 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65721366, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (74271600).

65721366 is an abundant number, since it is smaller than the sum of its proper divisors (82821834).

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

65721366 is a wasteful number, since it uses less digits than its factorization.

65721366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1093 (or 1090 counting only the distinct ones).

The product of its digits is 45360, while the sum is 36.

The square root of 65721366 is about 8106.8715297579. The cubic root of 65721366 is about 403.5544994402.

The spelling of 65721366 in words is "sixty-five million, seven hundred twenty-one thousand, three hundred sixty-six".