64117821 has 8 divisors (see below), whose sum is σ = 85548384. Its totient is φ = 42716240.

The previous prime is 64117817. The next prime is 64117831. The reversal of 64117821 is 12871146.

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

It is a cyclic number.

It is not a de Polignac number, because 64117821 - 2² = 64117817 is a prime.

It is a super-2 number, since 2×64117821² = 8222189939576082, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64117831) 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, 1410 + ... + 11411.

It is an arithmetic number, because the mean of its divisors is an integer number (10693548).

Almost surely, 2^64117821 is an apocalyptic number.

It is an amenable number.

64117821 is a deficient number, since it is larger than the sum of its proper divisors (21430563).

64117821 is a wasteful number, since it uses less digits than its factorization.

64117821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14491.

The product of its digits is 2688, while the sum is 30.

The square root of 64117821 is about 8007.3604265076. The cubic root of 64117821 is about 400.2453099435.

Adding to 64117821 its reverse (12871146), we get a palindrome (76988967).

The spelling of 64117821 in words is "sixty-four million, one hundred seventeen thousand, eight hundred twenty-one".