64983781 has 12 divisors (see below), whose sum is σ = 70701600. Its totient is φ = 59560920.

The previous prime is 64983773. The next prime is 64983827. The reversal of 64983781 is 18738946.

It is a happy number.

It is not a de Polignac number, because 64983781 - 2³ = 64983773 is a prime.

It is a super-2 number, since 2×64983781² = 8445783586111922, 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 (64980781) 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 11 ways as a sum of consecutive naturals, for example, 16480 + ... + 20038.

It is an arithmetic number, because the mean of its divisors is an integer number (5891800).

Almost surely, 2^64983781 is an apocalyptic number.

It is an amenable number.

64983781 is a deficient number, since it is larger than the sum of its proper divisors (5717819).

64983781 is a wasteful number, since it uses less digits than its factorization.

64983781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3640 (or 3609 counting only the distinct ones).

The product of its digits is 290304, while the sum is 46.

The square root of 64983781 is about 8061.2518258643. The cubic root of 64983781 is about 402.0391309482.

The spelling of 64983781 in words is "sixty-four million, nine hundred eighty-three thousand, seven hundred eighty-one".