65781438 has 8 divisors (see below), whose sum is σ = 131562888. Its totient is φ = 21927144.

The previous prime is 65781437. The next prime is 65781451. The reversal of 65781438 is 83418756.

It is a sphenic number, since it is the product of 3 distinct primes.

65781438 is an admirable number.

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 65781438.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65781433) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5481781 + ... + 5481792.

It is an arithmetic number, because the mean of its divisors is an integer number (16445361).

Almost surely, 2^65781438 is an apocalyptic number.

65781438 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

65781438 is a wasteful number, since it uses less digits than its factorization.

65781438 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10963578.

The product of its digits is 161280, while the sum is 42.

The square root of 65781438 is about 8110.5756885686. The cubic root of 65781438 is about 403.6774170693.

The spelling of 65781438 in words is "sixty-five million, seven hundred eighty-one thousand, four hundred thirty-eight".