30721253 has 2 divisors, whose sum is σ = 30721254. Its totient is φ = 30721252.

The previous prime is 30721231. The next prime is 30721277. The reversal of 30721253 is 35212703.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 30283009 + 438244 = 5503^2 + 662^2 .

It is an emirp because it is prime and its reverse (35212703) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 30721253 - 2⁶ = 30721189 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (30721213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15360626 + 15360627.

It is an arithmetic number, because the mean of its divisors is an integer number (15360627).

Almost surely, 2^30721253 is an apocalyptic number.

It is an amenable number.

30721253 is a deficient number, since it is larger than the sum of its proper divisors (1).

30721253 is an equidigital number, since it uses as much as digits as its factorization.

30721253 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1260, while the sum is 23.

The square root of 30721253 is about 5542.6756174252. The cubic root of 30721253 is about 313.1936693338.

Adding to 30721253 its reverse (35212703), we get a palindrome (65933956).

The spelling of 30721253 in words is "thirty million, seven hundred twenty-one thousand, two hundred fifty-three".