65312240 has 80 divisors (see below), whose sum is σ = 174655488. Its totient is φ = 22249728.

The previous prime is 65312231. The next prime is 65312243. The reversal of 65312240 is 4221356.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65312243) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 124619 + ... + 125141.

Almost surely, 2^65312240 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 65312240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87327744).

65312240 is an abundant number, since it is smaller than the sum of its proper divisors (109343248).

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

65312240 is a wasteful number, since it uses less digits than its factorization.

65312240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 766 (or 760 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 23.

The square root of 65312240 is about 8081.5988517125. The cubic root of 65312240 is about 402.7153586913.

Adding to 65312240 its reverse (4221356), we get a palindrome (69533596).

The spelling of 65312240 in words is "sixty-five million, three hundred twelve thousand, two hundred forty".