65781240 has 64 divisors (see below), whose sum is σ = 225538560. Its totient is φ = 15035520.

The previous prime is 65781239. The next prime is 65781263. The reversal of 65781240 is 4218756.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 38316 + ... + 39995.

It is an arithmetic number, because the mean of its divisors is an integer number (3524040).

Almost surely, 2^65781240 is an apocalyptic number.

65781240 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

65781240 is an abundant number, since it is smaller than the sum of its proper divisors (159757320).

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

65781240 is a wasteful number, since it uses less digits than its factorization.

65781240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78332 (or 78328 counting only the distinct ones).

The product of its (nonzero) digits is 13440, while the sum is 33.

The square root of 65781240 is about 8110.5634822742. The cubic root of 65781240 is about 403.6770120503.

Adding to 65781240 its reverse (4218756), we get a palindrome (69999996).

The spelling of 65781240 in words is "sixty-five million, seven hundred eighty-one thousand, two hundred forty".