64830781 has 4 divisors (see below), whose sum is σ = 64846912. Its totient is φ = 64814652.

The previous prime is 64830691. The next prime is 64830791. The reversal of 64830781 is 18703846.

It is a happy number.

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, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 64830781 - 2¹¹ = 64828733 is a prime.

It is a super-2 number, since 2×64830781² = 8406060330139922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 64830781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64830791) 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, 3340 + ... + 11866.

It is an arithmetic number, because the mean of its divisors is an integer number (16211728).

Almost surely, 2^64830781 is an apocalyptic number.

It is an amenable number.

64830781 is a deficient number, since it is larger than the sum of its proper divisors (16131).

64830781 is an equidigital number, since it uses as much as digits as its factorization.

64830781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16130.

The product of its (nonzero) digits is 32256, while the sum is 37.

The square root of 64830781 is about 8051.7563922414. The cubic root of 64830781 is about 401.7233581783.

The spelling of 64830781 in words is "sixty-four million, eight hundred thirty thousand, seven hundred eighty-one".