63891995 has 4 divisors (see below), whose sum is σ = 76670400. Its totient is φ = 51113592.

The previous prime is 63891991. The next prime is 63892013. The reversal of 63891995 is 59919836.

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

It is a cyclic number.

It is not a de Polignac number, because 63891995 - 2² = 63891991 is a prime.

It is not an unprimeable number, because it can be changed into a prime (63891991) 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, 6389195 + ... + 6389204.

It is an arithmetic number, because the mean of its divisors is an integer number (19167600).

Almost surely, 2^63891995 is an apocalyptic number.

63891995 is a deficient number, since it is larger than the sum of its proper divisors (12778405).

63891995 is a wasteful number, since it uses less digits than its factorization.

63891995 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12778404.

The product of its digits is 524880, while the sum is 50.

The square root of 63891995 is about 7993.2468371745. The cubic root of 63891995 is about 399.7748628903.

The spelling of 63891995 in words is "sixty-three million, eight hundred ninety-one thousand, nine hundred ninety-five".