63918961 has 8 divisors (see below), whose sum is σ = 65058048. Its totient is φ = 62790000.

The previous prime is 63918949. The next prime is 63918971. The reversal of 63918961 is 16981936.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-63918961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (63918971) 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, 10816 + ... + 15646.

It is an arithmetic number, because the mean of its divisors is an integer number (8132256).

Almost surely, 2^63918961 is an apocalyptic number.

It is an amenable number.

63918961 is a deficient number, since it is larger than the sum of its proper divisors (1139087).

63918961 is a wasteful number, since it uses less digits than its factorization.

63918961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5063.

The product of its digits is 69984, while the sum is 43.

The square root of 63918961 is about 7994.9334581346. The cubic root of 63918961 is about 399.8310974399.

It can be divided in two parts, 639 and 18961, that added together give a square (19600 = 140²).

The spelling of 63918961 in words is "sixty-three million, nine hundred eighteen thousand, nine hundred sixty-one".