63729621 has 12 divisors (see below), whose sum is σ = 94299660. Its totient is φ = 41449920.

The previous prime is 63729613. The next prime is 63729623. The reversal of 63729621 is 12692736.

63729621 is a `hidden beast` number, since 6 + 3 + 7 + 29 + 621 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 35533521 + 28196100 = 5961^2 + 5310^2 .

It is not a de Polignac number, because 63729621 - 2³ = 63729613 is a prime.

It is a super-2 number, since 2×63729621² = 8122929185607282, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63729623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 85986 + ... + 86723.

It is an arithmetic number, because the mean of its divisors is an integer number (7858305).

Almost surely, 2^63729621 is an apocalyptic number.

It is an amenable number.

63729621 is a deficient number, since it is larger than the sum of its proper divisors (30570039).

63729621 is a wasteful number, since it uses less digits than its factorization.

63729621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172756 (or 172753 counting only the distinct ones).

The product of its digits is 27216, while the sum is 36.

The square root of 63729621 is about 7983.0834268470. The cubic root of 63729621 is about 399.4359153118.

The spelling of 63729621 in words is "sixty-three million, seven hundred twenty-nine thousand, six hundred twenty-one".