64147681 has 16 divisors (see below), whose sum is σ = 75675600. Its totient is φ = 53803008.

The previous prime is 64147663. The next prime is 64147697. The reversal of 64147681 is 18674146.

It is a happy number.

64147681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 8 ways, for example, as 6630625 + 57517056 = 2575^2 + 7584^2 .

It is a cyclic number.

It is not a de Polignac number, because 64147681 - 2¹¹ = 64145633 is a prime.

It is a super-2 number, since 2×64147681² = 8229849955355522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 64147681.

It is not an unprimeable number, because it can be changed into a prime (64147081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1405 + ... + 11413.

It is an arithmetic number, because the mean of its divisors is an integer number (4729725).

Almost surely, 2^64147681 is an apocalyptic number.

It is an amenable number.

64147681 is a deficient number, since it is larger than the sum of its proper divisors (11527919).

64147681 is a wasteful number, since it uses less digits than its factorization.

64147681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10068.

The product of its digits is 32256, while the sum is 37.

The square root of 64147681 is about 8009.2247440061. The cubic root of 64147681 is about 400.3074324028.

The spelling of 64147681 in words is "sixty-four million, one hundred forty-seven thousand, six hundred eighty-one".