53681665 has 8 divisors (see below), whose sum is σ = 68207400. Its totient is φ = 40419072.

The previous prime is 53681657. The next prime is 53681671. The reversal of 53681665 is 56618635.

It can be written as a sum of positive squares in 4 ways, for example, as 7997584 + 45684081 = 2828^2 + 6759^2 .

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 53681665 - 2³ = 53681657 is a prime.

It is an unprimeable number.

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, 315690 + ... + 315859.

It is an arithmetic number, because the mean of its divisors is an integer number (8525925).

Almost surely, 2^53681665 is an apocalyptic number.

It is an amenable number.

53681665 is a deficient number, since it is larger than the sum of its proper divisors (14525735).

53681665 is a wasteful number, since it uses less digits than its factorization.

53681665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 631571.

The product of its digits is 129600, while the sum is 40.

The square root of 53681665 is about 7326.7772587953. Note that the first 3 decimals coincide. The cubic root of 53681665 is about 377.2321155474.

The spelling of 53681665 in words is "fifty-three million, six hundred eighty-one thousand, six hundred sixty-five".