63729661 has 4 divisors (see below), whose sum is σ = 63900892. Its totient is φ = 63558432.

The previous prime is 63729649. The next prime is 63729683. The reversal of 63729661 is 16692736.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 50268100 + 13461561 = 7090^2 + 3669^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-63729661 is a prime.

It is a super-2 number, since 2×63729661² = 8122939382349842, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63729361) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85056 + ... + 85801.

It is an arithmetic number, because the mean of its divisors is an integer number (15975223).

Almost surely, 2^63729661 is an apocalyptic number.

It is an amenable number.

63729661 is a deficient number, since it is larger than the sum of its proper divisors (171231).

63729661 is a wasteful number, since it uses less digits than its factorization.

63729661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171230.

The product of its digits is 81648, while the sum is 40.

The square root of 63729661 is about 7983.0859321443. The cubic root of 63729661 is about 399.4359988806.

The spelling of 63729661 in words is "sixty-three million, seven hundred twenty-nine thousand, six hundred sixty-one".