63999993 has 8 divisors (see below), whose sum is σ = 85370400. Its totient is φ = 42648128.

The previous prime is 63999979. The next prime is 64000031. The reversal of 63999993 is 39999936.

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 63999993 - 2¹⁴ = 63983609 is a prime.

It is not an unprimeable number, because it can be changed into a prime (63999913) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10273 + ... + 15281.

It is an arithmetic number, because the mean of its divisors is an integer number (10671300).

Almost surely, 2^63999993 is an apocalyptic number.

It is an amenable number.

63999993 is a deficient number, since it is larger than the sum of its proper divisors (21370407).

63999993 is a wasteful number, since it uses less digits than its factorization.

63999993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9271.

The product of its digits is 3188646, while the sum is 57.

The square root of 63999993 is about 7999.9995625000. Note that the first 3 decimals coincide. The cubic root of 63999993 is about 399.9999854167. Note that the first 4 decimals are identical.

Subtracting from 63999993 its sum of digits (57), we obtain a palindrome (63999936).

The spelling of 63999993 in words is "sixty-three million, nine hundred ninety-nine thousand, nine hundred ninety-three".