30821664721 has 5 divisors (see below), whose sum is σ = 30895400761. Its totient is φ = 30748104662.

The previous prime is 30821664703. The next prime is 30821664733. The reversal of 30821664721 is 12746612803.

The square root of 30821664721 is 175561.

It is a perfect power (a square, a biquadrate), and thus also a powerful number.

It is not a de Polignac number, because 30821664721 - 2¹⁹ = 30821140433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (30821664791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 4 ways as a sum of consecutive naturals, for example, 73559850 + ... + 73560268.

Almost surely, 2^30821664721 is an apocalyptic number.

30821664721 is the 175561-st square number.

30821664721 is the 87781-st centered octagonal number.

It is an amenable number.

30821664721 is a deficient number, since it is larger than the sum of its proper divisors (73736040).

30821664721 is an frugal number, since it uses more digits than its factorization.

30821664721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1676 (or 419 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 40.

The spelling of 30821664721 in words is "thirty billion, eight hundred twenty-one million, six hundred sixty-four thousand, seven hundred twenty-one".