64538881 has 8 divisors (see below), whose sum is σ = 70465824. Its totient is φ = 58621920.

The previous prime is 64538867. The next prime is 64538917. The reversal of 64538881 is 18883546.

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 64538881 - 2⁷ = 64538753 is a prime.

It is a super-2 number, since 2×64538881² = 8330534321464322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (64538821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19510 + ... + 22576.

It is an arithmetic number, because the mean of its divisors is an integer number (8808228).

Almost surely, 2^64538881 is an apocalyptic number.

It is an amenable number.

64538881 is a deficient number, since it is larger than the sum of its proper divisors (5926943).

64538881 is a wasteful number, since it uses less digits than its factorization.

64538881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4991.

The product of its digits is 184320, while the sum is 43.

The square root of 64538881 is about 8033.6094627508. The cubic root of 64538881 is about 401.1195324445.

The spelling of 64538881 in words is "sixty-four million, five hundred thirty-eight thousand, eight hundred eighty-one".