863649681 has 16 divisors (see below), whose sum is σ = 1186462080. Its totient is φ = 558546560.

The previous prime is 863649659. The next prime is 863649697. The reversal of 863649681 is 186946368.

It is a cyclic number.

It is not a de Polignac number, because 863649681 - 2⁵ = 863649649 is a prime.

It is a super-2 number, since 2×863649681² = 1491781542982803522, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (863649481) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16365 + ... + 44666.

It is an arithmetic number, because the mean of its divisors is an integer number (74153880).

Almost surely, 2^863649681 is an apocalyptic number.

It is an amenable number.

863649681 is a deficient number, since it is larger than the sum of its proper divisors (322812399).

863649681 is a wasteful number, since it uses less digits than its factorization.

863649681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61176.

The product of its digits is 1492992, while the sum is 51.

The square root of 863649681 is about 29387.9172620313. The cubic root of 863649681 is about 952.3118876798.

The spelling of 863649681 in words is "eight hundred sixty-three million, six hundred forty-nine thousand, six hundred eighty-one".