65971640 has 96 divisors (see below), whose sum is σ = 174953520. Its totient is φ = 22321152.

The previous prime is 65971601. The next prime is 65971693. The reversal of 65971640 is 4617956.

It is a junction number, because it is equal to n+sod(n) for n = 65971594 and 65971603.

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, 189947 + ... + 190293.

Almost surely, 2^65971640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 65971640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87476760).

65971640 is an abundant number, since it is smaller than the sum of its proper divisors (108981880).

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

65971640 is a wasteful number, since it uses less digits than its factorization.

65971640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 469 (or 458 counting only the distinct ones).

The product of its (nonzero) digits is 45360, while the sum is 38.

The square root of 65971640 is about 8122.2927797513. The cubic root of 65971640 is about 404.0661101497.

The spelling of 65971640 in words is "sixty-five million, nine hundred seventy-one thousand, six hundred forty".