64838981 has 8 divisors (see below), whose sum is σ = 66192120. Its totient is φ = 63490752.

The previous prime is 64838927. The next prime is 64839017. The reversal of 64838981 is 18983846.

It can be written as a sum of positive squares in 4 ways, for example, as 36120100 + 28718881 = 6010^2 + 5359^2 .

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64838981 is a prime.

It is a super-2 number, since 2×64838981² = 8408186914236722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64838681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 38015 + ... + 39683.

It is an arithmetic number, because the mean of its divisors is an integer number (8274015).

Almost surely, 2^64838981 is an apocalyptic number.

It is an amenable number.

64838981 is a deficient number, since it is larger than the sum of its proper divisors (1353139).

64838981 is a wasteful number, since it uses less digits than its factorization.

64838981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2455.

The product of its digits is 331776, while the sum is 47.

The square root of 64838981 is about 8052.2655818099. The cubic root of 64838981 is about 401.7402945400.

The spelling of 64838981 in words is "sixty-four million, eight hundred thirty-eight thousand, nine hundred eighty-one".