63139681 has 4 divisors (see below), whose sum is σ = 68879664. Its totient is φ = 57399700.

The previous prime is 63139639. The next prime is 63139691. The reversal of 63139681 is 18693136.

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 63139681 - 2⁷ = 63139553 is a prime.

It is a super-2 number, since 2×63139681² = 7973238633563522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 63139681.

It is not an unprimeable number, because it can be changed into a prime (63139691) 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, 2869975 + ... + 2869996.

It is an arithmetic number, because the mean of its divisors is an integer number (17219916).

Almost surely, 2^63139681 is an apocalyptic number.

It is an amenable number.

63139681 is a deficient number, since it is larger than the sum of its proper divisors (5739983).

63139681 is a wasteful number, since it uses less digits than its factorization.

63139681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5739982.

The product of its digits is 23328, while the sum is 37.

The square root of 63139681 is about 7946.0481372818. The cubic root of 63139681 is about 398.1995771020.

The spelling of 63139681 in words is "sixty-three million, one hundred thirty-nine thousand, six hundred eighty-one".