30721533056 has 16 divisors (see below), whose sum is σ = 61203054390. Its totient is φ = 15360766464.

The previous prime is 30721533053. The next prime is 30721533071. The reversal of 30721533056 is 65033512703.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 25669166656 + 5052366400 = 160216^2 + 71080^2 .

It is a tau number, because it is divible by the number of its divisors (16).

It is not an unprimeable number, because it can be changed into a prime (30721533053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 120005861 + ... + 120006116.

Almost surely, 2^30721533056 is an apocalyptic number.

It is an amenable number.

30721533056 is a deficient number, since it is larger than the sum of its proper divisors (30481521334).

30721533056 is an equidigital number, since it uses as much as digits as its factorization.

30721533056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240011991 (or 240011979 counting only the distinct ones).

The product of its (nonzero) digits is 56700, while the sum is 35.

The spelling of 30721533056 in words is "thirty billion, seven hundred twenty-one million, five hundred thirty-three thousand, fifty-six".