8721260644 has 24 divisors (see below), whose sum is σ = 16168965120. Its totient is φ = 4101841536.

The previous prime is 8721260609. The next prime is 8721260657. The reversal of 8721260644 is 4460621278.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 8721260597 and 8721260606.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90877 + ... + 160315.

It is an arithmetic number, because the mean of its divisors is an integer number (673706880).

Almost surely, 2^8721260644 is an apocalyptic number.

It is an amenable number.

8721260644 is a deficient number, since it is larger than the sum of its proper divisors (7447704476).

8721260644 is a wasteful number, since it uses less digits than its factorization.

8721260644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71307 (or 71305 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 40.

The square root of 8721260644 is about 93387.6900024837. The cubic root of 8721260644 is about 2058.3841166109.

The spelling of 8721260644 in words is "eight billion, seven hundred twenty-one million, two hundred sixty thousand, six hundred forty-four".