64718881 has 8 divisors (see below), whose sum is σ = 69206184. Its totient is φ = 60307200.

The previous prime is 64718879. The next prime is 64718911. The reversal of 64718881 is 18881746.

It can be written as a sum of positive squares in 4 ways, for example, as 23232400 + 41486481 = 4820^2 + 6441^2 .

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 64718881 - 2¹ = 64718879 is a prime.

It is a super-2 number, since 2×64718881² = 8377067115784322, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (64718831) 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, 17130 + ... + 20563.

It is an arithmetic number, because the mean of its divisors is an integer number (8650773).

Almost surely, 2^64718881 is an apocalyptic number.

It is an amenable number.

64718881 is a deficient number, since it is larger than the sum of its proper divisors (4487303).

64718881 is a wasteful number, since it uses less digits than its factorization.

64718881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37811.

The product of its digits is 86016, while the sum is 43.

The square root of 64718881 is about 8044.8045967568. The cubic root of 64718881 is about 401.4920959535.

The spelling of 64718881 in words is "sixty-four million, seven hundred eighteen thousand, eight hundred eighty-one".