30791500721 has 2 divisors, whose sum is σ = 30791500722. Its totient is φ = 30791500720.

The previous prime is 30791500693. The next prime is 30791500777. The reversal of 30791500721 is 12700519703.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20025363121 + 10766137600 = 141511^2 + 103760^2 .

It is an emirp because it is prime and its reverse (12700519703) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 30791500721 - 2⁶ = 30791500657 is a prime.

It is not a weakly prime, because it can be changed into another prime (30791500921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15395750360 + 15395750361.

It is an arithmetic number, because the mean of its divisors is an integer number (15395750361).

Almost surely, 2^30791500721 is an apocalyptic number.

It is an amenable number.

30791500721 is a deficient number, since it is larger than the sum of its proper divisors (1).

30791500721 is an equidigital number, since it uses as much as digits as its factorization.

30791500721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13230, while the sum is 35.

The spelling of 30791500721 in words is "thirty billion, seven hundred ninety-one million, five hundred thousand, seven hundred twenty-one".