63816961 has 4 divisors (see below), whose sum is σ = 68725972. Its totient is φ = 58907952.

The previous prime is 63816959. The next prime is 63817009. The reversal of 63816961 is 16961836.

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 22137025 + 41679936 = 4705^2 + 6456^2 .

It is a cyclic number.

It is not a de Polignac number, because 63816961 - 2¹ = 63816959 is a prime.

It is a super-2 number, since 2×63816961² = 8145209022551042, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (63816931) 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, 2454486 + ... + 2454511.

It is an arithmetic number, because the mean of its divisors is an integer number (17181493).

Almost surely, 2^63816961 is an apocalyptic number.

It is an amenable number.

63816961 is a deficient number, since it is larger than the sum of its proper divisors (4909011).

63816961 is a wasteful number, since it uses less digits than its factorization.

63816961 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4909010.

The product of its digits is 46656, while the sum is 40.

The square root of 63816961 is about 7988.5518712718. The cubic root of 63816961 is about 399.6183046375.

The spelling of 63816961 in words is "sixty-three million, eight hundred sixteen thousand, nine hundred sixty-one".