30873721 has 2 divisors, whose sum is σ = 30873722. Its totient is φ = 30873720.

The previous prime is 30873701. The next prime is 30873749. The reversal of 30873721 is 12737803.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 28944400 + 1929321 = 5380^2 + 1389^2 .

It is a cyclic number.

It is not a de Polignac number, because 30873721 - 2¹⁹ = 30349433 is a prime.

It is not a weakly prime, because it can be changed into another prime (30873701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15436860 + 15436861.

It is an arithmetic number, because the mean of its divisors is an integer number (15436861).

Almost surely, 2^30873721 is an apocalyptic number.

It is an amenable number.

30873721 is a deficient number, since it is larger than the sum of its proper divisors (1).

30873721 is an equidigital number, since it uses as much as digits as its factorization.

30873721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 30873721 is about 5556.4126016703. The cubic root of 30873721 is about 313.7109359152.

The spelling of 30873721 in words is "thirty million, eight hundred seventy-three thousand, seven hundred twenty-one".