64006681 has 4 divisors (see below), whose sum is σ = 65091600. Its totient is φ = 62921764.

The previous prime is 64006673. The next prime is 64006721. The reversal of 64006681 is 18660046.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 64006681 - 2³ = 64006673 is a prime.

It is a super-2 number, since 2×64006681² = 8193710425271522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (64046681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 542371 + ... + 542488.

It is an arithmetic number, because the mean of its divisors is an integer number (16272900).

Almost surely, 2^64006681 is an apocalyptic number.

It is an amenable number.

64006681 is a deficient number, since it is larger than the sum of its proper divisors (1084919).

64006681 is a wasteful number, since it uses less digits than its factorization.

64006681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1084918.

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 64006681 is about 8000.4175516032. The cubic root of 64006681 is about 400.0139182657.

The spelling of 64006681 in words is "sixty-four million, six thousand, six hundred eighty-one".