63999857 has 4 divisors (see below), whose sum is σ = 64115316. Its totient is φ = 63884400.

The previous prime is 63999833. The next prime is 63999907. The reversal of 63999857 is 75899936.

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 2283121 + 61716736 = 1511^2 + 7856^2 .

It is a cyclic number.

It is not a de Polignac number, because 63999857 - 2¹² = 63995761 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (63999457) 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, 56894 + ... + 58007.

It is an arithmetic number, because the mean of its divisors is an integer number (16028829).

Almost surely, 2^63999857 is an apocalyptic number.

It is an amenable number.

63999857 is a deficient number, since it is larger than the sum of its proper divisors (115459).

63999857 is a wasteful number, since it uses less digits than its factorization.

63999857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115458.

The product of its digits is 3674160, while the sum is 56.

The square root of 63999857 is about 7999.9910624950. The cubic root of 63999857 is about 399.9997020831. Note that the first 3 decimals are identical.

The spelling of 63999857 in words is "sixty-three million, nine hundred ninety-nine thousand, eight hundred fifty-seven".