64889921 has 8 divisors (see below), whose sum is σ = 69972000. Its totient is φ = 59974560.

The previous prime is 64889917. The next prime is 64889963. The reversal of 64889921 is 12998846.

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 64889921 - 2² = 64889917 is a prime.

It is a super-4 number, since 4×64889921⁴ (a number of 32 digits) contains 4444 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64889521) 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, 40871 + ... + 42428.

It is an arithmetic number, because the mean of its divisors is an integer number (8746500).

Almost surely, 2^64889921 is an apocalyptic number.

It is an amenable number.

64889921 is a deficient number, since it is larger than the sum of its proper divisors (5082079).

64889921 is a wasteful number, since it uses less digits than its factorization.

64889921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83359.

The product of its digits is 248832, while the sum is 47.

The square root of 64889921 is about 8055.4280457341. The cubic root of 64889921 is about 401.8454745482.

The spelling of 64889921 in words is "sixty-four million, eight hundred eighty-nine thousand, nine hundred twenty-one".