65403781 has 4 divisors (see below), whose sum is σ = 65508064. Its totient is φ = 65299500.

The previous prime is 65403763. The next prime is 65403797. The reversal of 65403781 is 18730456.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 65403781 - 2⁹ = 65403269 is a prime.

It is a super-2 number, since 2×65403781² = 8555309138191922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (65403721) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 51195 + ... + 52456.

It is an arithmetic number, because the mean of its divisors is an integer number (16377016).

Almost surely, 2^65403781 is an apocalyptic number.

It is an amenable number.

65403781 is a deficient number, since it is larger than the sum of its proper divisors (104283).

65403781 is a wasteful number, since it uses less digits than its factorization.

65403781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104282.

The product of its (nonzero) digits is 20160, while the sum is 34.

The square root of 65403781 is about 8087.2604137619. The cubic root of 65403781 is about 402.9034181671.

The spelling of 65403781 in words is "sixty-five million, four hundred three thousand, seven hundred eighty-one".